diff --git a/src/err_netconf.c b/src/err_netconf.c
index 519cea8b..99dd6e6a 100644
--- a/src/err_netconf.c
+++ b/src/err_netconf.c
@@ -122,6 +122,12 @@ np_err_missing_element(sr_session_ctx_t *ev_sess, const char *elem_name)
     sr_session_set_netconf_error(ev_sess, "protocol", "missing-element", NULL, NULL, msg, 1, "bad-element", elem_name);
 }
 
+void
+np_err_missing_attribute(sr_session_ctx_t *ev_sess, const char *message, const char *elem_name)
+{
+    sr_session_set_netconf_error(ev_sess, "protocol", "missing-attribute", NULL, NULL, message, 1, "bad-element", elem_name);
+}
+
 void
 np_err_bad_element(sr_session_ctx_t *ev_sess, const char *elem_name, const char *description)
 {
diff --git a/src/err_netconf.h b/src/err_netconf.h
index b9bf4ace..0a142f1e 100644
--- a/src/err_netconf.h
+++ b/src/err_netconf.h
@@ -31,6 +31,8 @@ void np_err_lock_denied(sr_session_ctx_t *ev_sess, const char *err_msg, uint32_t
 
 void np_err_missing_element(sr_session_ctx_t *ev_sess, const char *elem_name);
 
+void np_err_missing_attribute(sr_session_ctx_t *ev_sess, const char *message, const char *elem_name);
+
 void np_err_bad_element(sr_session_ctx_t *ev_sess, const char *elem_name, const char *description);
 
 void np_err_invalid_value(sr_session_ctx_t *ev_sess, const char *description, const char *bad_elem_name);
diff --git a/src/main.c b/src/main.c
index 9a161afe..7cf3e30b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -249,6 +249,64 @@ np2srv_err_nc(sr_error_info_err_t *err)
     return NULL;
 }
 
+/**
+ * @brief Find the nth substring delimited by quotes.
+ *
+ * For example: abcd"ef"ghij"kl"mn -> index 0 is "ef", index 1 is "kl".
+ *
+ * @param[in] msg Input string with quoted substring.
+ * @param[in] index Number starting from 0 specifying the nth substring.
+ * @return Copied nth substring without quotes.
+ */
+static char *
+np2srv_err_reply_get_quoted_string(const char *msg, uint32_t index)
+{
+    char *ret;
+    const char *start = NULL, *end = NULL, *iter, *tmp;
+    uint32_t quote_cnt = 0, last_quote;
+
+    assert(msg);
+
+    last_quote = (index + 1) * 2;
+    for (iter = msg; *iter; ++iter) {
+        if (*iter != '\"') {
+            continue;
+        }
+        /* updating the start and end pointers - swap */
+        tmp = end;
+        end = iter;
+        start = tmp;
+        if (++quote_cnt == last_quote) {
+            /* nth substring found */
+            break;
+        }
+    }
+
+    if (!start) {
+        return NULL;
+    }
+
+    /* Skip first quote */
+    ++start;
+    /* Copy substring */
+    ret = strndup(start, end - start);
+
+    return ret;
+}
+
+/**
+ * @brief Check that the @p str starts with the @p prefix.
+ *
+ * @param[in] prefix Required prefix.
+ * @param[in] str Input string to check.
+ * @return True if @p str start with @p prefix otherwise False.
+ */
+static ly_bool
+np2srv_strstarts(const char *prefix, const char *str)
+{
+    return strncmp(str, prefix, strlen(prefix)) == 0;
+}
+
 /**
  * @brief Create NC error reply based on SR error info.
  *
@@ -262,6 +320,9 @@ np2srv_err_reply_sr(const sr_error_info_t *err_info)
     struct lyd_node *e;
     const struct ly_ctx *ly_ctx;
     size_t i;
+    char *str, *path;
+    const struct lysc_node *cn;
+    NC_ERR_TYPE errtype;
 
     /* try to find a NETCONF error(s) */
     for (i = 0; i < err_info->err_count; ++i) {
@@ -284,16 +345,34 @@ np2srv_err_reply_sr(const sr_error_info_t *err_info)
 
     ly_ctx = sr_acquire_context(np2srv.sr_conn);
     for (i = 0; i < err_info->err_count; ++i) {
-        /* generic error */
-        e = nc_err(ly_ctx, NC_ERR_OP_FAILED, NC_ERR_TYPE_APP);
-        nc_err_set_msg(e, err_info->err[i].message, "en");
+        if (np2srv_strstarts("Mandatory node", err_info->err[i].message) ||
+                np2srv_strstarts("Mandatory choice", err_info->err[i].message)) {
+            str = np2srv_err_reply_get_quoted_string(err_info->err[i].message, 0);
+            path = np2srv_err_reply_get_quoted_string(err_info->err[i].message, 1);
+            cn = lys_find_path(ly_ctx, NULL, path, 0);
+            if (cn && ((cn->nodetype & LYS_RPC) || (cn->nodetype & LYS_INPUT))) {
+                errtype = NC_ERR_TYPE_PROT;
+            } else {
+                errtype = NC_ERR_TYPE_APP;
+            }
+            e = nc_err(ly_ctx, NC_ERR_MISSING_ELEM, errtype, str);
+            free(str);
+            free(path);
+        } else if (err_info->err->err_code == SR_ERR_NO_MEMORY) {
+            e = nc_err(ly_ctx, NC_ERR_RES_DENIED, NC_ERR_TYPE_APP);
+        } else {
+            /* generic error */
+            e = nc_err(ly_ctx, NC_ERR_OP_FAILED, NC_ERR_TYPE_APP);
+        }
 
+        nc_err_set_msg(e, err_info->err[i].message, "en");
         if (reply) {
             nc_server_reply_add_err(reply, e);
         } else {
             reply = nc_server_reply_err(e);
         }
     }
+    /* clear for other errors */
     sr_release_context(np2srv.sr_conn);
 
     return reply;
diff --git a/src/netconf.c b/src/netconf.c
index 31dd5901..e0b790fb 100644
--- a/src/netconf.c
+++ b/src/netconf.c
@@ -155,7 +155,7 @@ np2srv_rpc_get_cb(sr_session_ctx_t *session, uint32_t UNUSED(sub_id), const char
         if (meta && !strcmp(lyd_get_meta_value(meta), "xpath")) {
             meta = lyd_find_meta(node->meta, NULL, "ietf-netconf:select");
             if (!meta) {
-                ERR("RPC with an XPath filter without the \"select\" attribute.");
+                np_err_missing_attribute(session, "Missing \"select\" attribute", "filter");
                 rc = SR_ERR_INVAL_ARG;
                 goto cleanup;
             }
@@ -933,7 +933,7 @@ np2srv_rpc_subscribe_cb(sr_session_ctx_t *session, uint32_t UNUSED(sub_id), cons
         if (meta && !strcmp(lyd_get_meta_value(meta), "xpath")) {
             meta = lyd_find_meta(node->meta, NULL, "ietf-netconf:select");
             if (!meta) {
-                ERR("RPC with an XPath filter without the \"select\" attribute.");
+                np_err_missing_attribute(session, "Missing \"select\" attribute", "filter");
                 rc = SR_ERR_INVAL_ARG;
                 goto cleanup;
             }
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 805e8c8f..75c186c2 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -38,11 +38,11 @@ include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 include_directories(${CMAKE_CURRENT_BINARY_DIR})
 
 # base test source
-set(TEST_SRC "np2_test.c")
+set(TEST_SRC "np2_test.c" "np2_other_client.c")
 
 # list of all the tests
 set(TESTS test_rpc test_edit test_filter test_subscribe_filter test_subscribe_param test_parallel_sessions
-    test_candidate test_with_defaults test_nacm test_sub_ntf test_sub_ntf_advanced test_sub_ntf_filter test_error)
+    test_candidate test_with_defaults test_nacm test_sub_ntf test_sub_ntf_advanced test_sub_ntf_filter test_error test_other_client)
 
 if(CMAKE_C_FLAGS MATCHES "-fsanitize=thread")
     message(WARNING "Features which use SIGEV_THREAD are known to be broken under TSAN, disabling tests for YANG-push and confirmed commit")
diff --git a/tests/np2_other_client.c b/tests/np2_other_client.c
new file mode 100644
index 00000000..f4ec6633
--- /dev/null
+++ b/tests/np2_other_client.c
@@ -0,0 +1,354 @@
+/**
+ * @file np2_other_client.c
+ * @author Adam Piecek <piecek@cesnet.cz>
+ * @brief An alternative test interface for communicating with the NETCONF server.
+ *
+ * @copyright
+ * Copyright (c) 2019 - 2024 Deutsche Telekom AG.
+ * Copyright (c) 2017 - 2024 CESNET, z.s.p.o.
+ *
+ * This source code is licensed under BSD 3-Clause License (the "License").
+ * You may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://opensource.org/licenses/BSD-3-Clause
+ */
+
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "libnetconf2/netconf.h"
+#include "np2_other_client.h"
+
+#define OC_FAIL_LOG \
+    fprintf(stderr, "Netconf client fail in %s:%d.\n", __FILE__, __LINE__)
+
+/**
+ * Full timeout of read or write in seconds.
+ */
+#define OC_TIMEOUT_SEC 60
+
+/**
+ * Microseconds after which tasks are repeated until the full timeout elapses.
+ */
+#define OC_TIMEOUT_STEP 100
+
+/**
+ * Check if the timeout has expired.
+ */
+#define OC_TIMEOUT(START_TIME) \
+    (((double)(time(NULL) - START_TIME)) > OC_TIMEOUT_SEC)
+
+/**
+ * @brief Write message to socket.
+ *
+ * @param[in] oc_sess Client session.
+ * @param[in] msg Message to send.
+ * @param[in] msglen Length of @p msg.
+ * @return 0 on success.
+ * @return negative number on error.
+ */
+static int
+oc_write(struct np_other_client *oc_sess, const char *msg, uint64_t msglen)
+{
+    uint64_t written = 0;
+    int64_t cnt;
+    int interrupted;
+
+    msglen = msglen ? msglen : strlen(msg);
+    do {
+        cnt = write(oc_sess->unixsock, msg + written, msglen - written);
+        written += cnt;
+        if ((cnt < 0) && (errno == EAGAIN)) {
+            cnt = 0;
+        } else if ((cnt < 0) && (errno == EINTR)) {
+            cnt = 0;
+            interrupted = 1;
+        } else if (cnt < 0) {
+            fprintf(stderr, "Socket error (%s).\n", strerror(errno));
+            return -1;
+        }
+        if ((cnt == 0) && !interrupted) {
+            /* we must wait */
+            usleep(OC_TIMEOUT_STEP);
+        }
+    } while (written < msglen);
+
+    return 0;
+}
+
+/**
+ * @brief Reallocation of internal buffer in the struct np_other_client.
+ *
+ * @param[in] oc_sess Client session.
+ * @return 0 on success.
+ * @return negative number on error.
+ */
+static int
+oc_realloc(struct np_other_client *oc_sess)
+{
+    void *tmp;
+
+    tmp = realloc(oc_sess->buf, oc_sess->bufsize * 2);
+    if (!tmp) {
+        fprintf(stderr, "Memory allocation error.\n");
+        return -1;
+    }
+    oc_sess->buf = tmp;
+    oc_sess->bufsize *= 2;
+
+    return 0;
+}
+
+/**
+ * @defgroup ocreadflags Flags for oc_read().
+ * @{
+ */
+#define OC_READ_HELLO_MSG 0x1   /**< read the response to the hello message from the server */
+/** @} ocreadflags */
+
+/**
+ * @brief Read message from socket.
+ *
+ * @param[in] oc_sess Client session.
+ * @param[in] flags Option for function (@ref ocreadflags).
+ * @return positive number representing number of characters written into @p oc_sess buffer.
+ * @return negative number on error.
+ */
+static int64_t
+oc_read(struct np_other_client *oc_sess, uint32_t flags)
+{
+    int64_t rd, rdall = 0;
+    time_t tm;
+    int interrupted;
+    const char *endtag;
+
+    tm = time(NULL);
+    oc_sess->buf[0] = 0;
+
+    do {
+        interrupted = 0;
+        rd = read(oc_sess->unixsock, oc_sess->buf + rdall, oc_sess->bufsize - rdall);
+        if (rd < 0) {
+            if (errno == EAGAIN) {
+                /* endtag not found */
+                rd = 0;
+            } else if (errno == EINTR) {
+                rd = 0;
+                interrupted = 1;
+                break;
+            } else {
+                fprintf(stderr, "Reading from file descriptor (%d) failed (%s).\n", oc_sess->unixsock, strerror(errno));
+                return -1;
+            }
+        } else if (rd == 0) {
+            fprintf(stderr, "Communication file descriptor (%d) unexpectedly closed.\n", oc_sess->unixsock);
+            return -1;
+        }
+        if (rd == 0) {
+            /* nothing read */
+            if (!interrupted) {
+                usleep(OC_TIMEOUT_STEP);
+            }
+            if (OC_TIMEOUT(tm)) {
+                /* waiting too long */
+                fprintf(stderr, "Message took too long to read\n");
+                return -1;
+            }
+        } else {
+            /* something read */
+            rdall += rd;
+        }
+
+        if ((flags & OC_READ_HELLO_MSG) && (rdall > 5)) {
+            /* check hello end tag, (strlen("]]>]]>") == 6) */
+            endtag = (oc_sess->buf + rdall) - 6;
+            if (!strncmp(endtag, "]]>]]>", 6)) {
+                /* success */
+                break;
+            }
+        } else if (rdall > 3) {
+            /* check classic end tag, (strlen(\n##\n) == 4) */
+            endtag = (oc_sess->buf + rdall) - 4;
+            if (!strncmp(endtag, "\n##\n", 4)) {
+                /* success */
+                break;
+            }
+        }
+
+        if ((oc_sess->bufsize - rdall) == 0) {
+            if (oc_realloc(oc_sess)) {
+                return -1;
+            }
+        }
+    } while (1);
+
+    return rdall;
+}
+
+/**
+ * @brief Establish NETCONF session.
+ *
+ * @param[in] oc_sess Client session.
+ * @return 0 on success.
+ */
+static int
+oc_hello_handshake(struct np_other_client *oc_sess)
+{
+    int rc;
+
+    const char *msg =
+            "<hello xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\">"
+            "<capabilities><capability>urn:ietf:params:netconf:base:1.0</capability>"
+            "<capability>urn:ietf:params:netconf:base:1.1</capability></capabilities></hello>]]>]]>";
+
+    rc = oc_write(oc_sess, msg, 0);
+    if (rc) {
+        return rc;
+    }
+
+    return (oc_read(oc_sess, OC_READ_HELLO_MSG) >= 0) ? 0 : -1;
+}
+
+struct np_other_client *
+oc_connect_unix(const char *address)
+{
+    struct sockaddr_un sun;
+    struct np_other_client *oc_sess = NULL;
+    int rc;
+
+    oc_sess = calloc(1, sizeof *oc_sess);
+    if (!oc_sess) {
+        OC_FAIL_LOG;
+        return NULL;
+    }
+
+    oc_sess->unixsock = socket(AF_UNIX, SOCK_STREAM, 0);
+    if (oc_sess->unixsock < 0) {
+        OC_FAIL_LOG;
+        return NULL;
+    }
+
+    memset(&sun, 0, sizeof(sun));
+    sun.sun_family = AF_UNIX;
+    snprintf(sun.sun_path, sizeof(sun.sun_path), "%s", address);
+
+    if (connect(oc_sess->unixsock, (struct sockaddr *)&sun, sizeof(sun)) < 0) {
+        OC_FAIL_LOG;
+        return NULL;
+    }
+
+    if (fcntl(oc_sess->unixsock, F_SETFL, O_NONBLOCK) < 0) {
+        OC_FAIL_LOG;
+        return NULL;
+    }
+
+    oc_sess->buf = malloc(2048);
+    if (!oc_sess->buf) {
+        return NULL;
+    }
+    oc_sess->bufsize = 2048;
+
+    rc = oc_hello_handshake(oc_sess);
+    if (rc) {
+        return NULL;
+    }
+
+    oc_sess->msgid = 1;
+
+    return oc_sess;
+}
+
+int
+oc_send_msg(struct np_other_client *oc_sess, const char *msg)
+{
+    int rc;
+    char *starttag = NULL;
+    uint64_t msglen;
+
+    /* increment message-id but do not increment after initial handshake */
+    oc_sess->msgid = (oc_sess->msgid != 1) ? oc_sess->msgid + 1 : oc_sess->msgid;
+
+    msglen = strlen(msg);
+    asprintf(&starttag, "\n#%" PRIu64 "\n", msglen);
+    if (!starttag) {
+        OC_FAIL_LOG;
+        return -1;
+        goto cleanup;
+    }
+
+    rc = oc_write(oc_sess, starttag, 0);
+    if (rc) {
+        OC_FAIL_LOG;
+        goto cleanup;
+    }
+    rc = oc_write(oc_sess, msg, msglen);
+    if (rc) {
+        OC_FAIL_LOG;
+        goto cleanup;
+    }
+    rc = oc_write(oc_sess, "\n##\n", 0);
+    if (rc) {
+        OC_FAIL_LOG;
+        goto cleanup;
+    }
+
+cleanup:
+    free(starttag);
+    return rc;
+}
+
+int
+oc_recv_msg(struct np_other_client *oc_sess, char **msg)
+{
+    int64_t len;
+    char *endtag;
+
+    len = oc_read(oc_sess, 0);
+
+    if (len < 0) {
+        return -1;
+    } else if (len == (int64_t)oc_sess->bufsize) {
+        /* unlikely, though no space for zero character */
+        if (oc_realloc(oc_sess)) {
+            return -1;
+        }
+    }
+
+    /* Delete end tag: \n##\n */
+    endtag = (oc_sess->buf + len) - 4;
+    *endtag = '\0';
+
+    /* Skip first start tag: \n##number\n */
+    *msg = strchr(oc_sess->buf + 1, '\n');
+    if (**msg == '\0') {
+        return -1;
+    }
+    *msg = *msg + 1;
+
+    return 0;
+}
+
+void
+oc_session_free(struct np_other_client *oc_sess)
+{
+    if (!oc_sess) {
+        return;
+    }
+    if (oc_sess->unixsock > 0) {
+        close(oc_sess->unixsock);
+    }
+    free(oc_sess->buf);
+    free(oc_sess);
+}
diff --git a/tests/np2_other_client.h b/tests/np2_other_client.h
new file mode 100644
index 00000000..6684bbd2
--- /dev/null
+++ b/tests/np2_other_client.h
@@ -0,0 +1,73 @@
+/**
+ * @file np2_other_client.h
+ * @author Adam Piecek <piecek@cesnet.cz>
+ * @brief An alternative test interface for communicating with the NETCONF server.
+ *
+ * @copyright
+ * Copyright (c) 2019 - 2024 Deutsche Telekom AG.
+ * Copyright (c) 2017 - 2024 CESNET, z.s.p.o.
+ *
+ * This source code is licensed under BSD 3-Clause License (the "License").
+ * You may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://opensource.org/licenses/BSD-3-Clause
+ */
+
+#ifndef _NP2_OTHER_CLIENT_H_
+#define _NP2_OTHER_CLIENT_H_
+
+#include "stdint.h"
+
+/**
+ * @brief Client session structure.
+ */
+struct np_other_client {
+    int unixsock;           /**< file descriptor of unix socket */
+    uint64_t msgid;         /**< message-id of the last message sent */
+    char *buf;              /**< private buffer used when reading a message */
+    uint64_t bufsize;       /**< size of np_other_client.buf */
+};
+
+/**
+ * @brief Connect to Netopeer server by unix socket.
+ *
+ * Function do not cover authentication or any other manipulation with the transport layer,
+ * it only establish NETCONF session by sending and processing NETCONF \<hello\> messages.
+ *
+ * @param[in] address Path to the unix socket.
+ * @return Client session structure or NULL.
+ */
+struct np_other_client *oc_connect_unix(const char *address);
+
+/**
+ * @brief Send message to server.
+ *
+ * @param[in] oc_sess Client session.
+ * @param[in] msg Message to send.
+ * @return 0 on success.
+ */
+int oc_send_msg(struct np_other_client *oc_sess, const char *msg);
+
+/**
+ * @brief Send message to server.
+ *
+ * As expected, the first start tag '\n##number\n' is not present in @p msg. But if the response is long,
+ * it will consist of several chunks, so there will be another start tag somewhere in the @p msg response.
+ * The implementation does not delete these internal start tags because this API is used for testing error
+ * messages that are not that long.
+ *
+ * @param[in] oc_sess Client session.
+ * @param[out] msg Received message. Do not deallocate memory.
+ * @return 0 on success.
+ */
+int oc_recv_msg(struct np_other_client *oc_sess, char **msg);
+
+/**
+ * @brief Release client session.
+ *
+ * @param[in] oc_sess Client session.
+ */
+void oc_session_free(struct np_other_client *oc_sess);
+
+#endif /* _NP2_OTHER_CLIENT_H_ */
diff --git a/tests/np2_test.c b/tests/np2_test.c
index f510e652..95930fc1 100644
--- a/tests/np2_test.c
+++ b/tests/np2_test.c
@@ -37,6 +37,7 @@
 #include <nc_client.h>
 #include <sysrepo/netconf_acm.h>
 
+#include "np2_other_client.h"
 #include "np2_test_config.h"
 
 #ifdef NETOPEER2_LIB
@@ -248,7 +249,7 @@ np2_glob_test_setup_sess_ctx(struct nc_session *sess, const char **modules)
 }
 
 int
-np2_glob_test_setup_server(void **state, const char *test_name, const char **modules)
+np2_glob_test_setup_server(void **state, const char *test_name, const char **modules, uint32_t flags)
 {
     struct np2_test *st;
     pid_t pid = 0;
@@ -432,22 +433,30 @@ np2_glob_test_setup_server(void **state, const char *test_name, const char **mod
     /* disable automatic YANG retrieval */
     nc_client_set_new_session_context_autofill(0);
 
-    /* create NETCONF sessions, with a single context */
-    st->nc_sess2 = nc_connect_unix(st->socket_path, NULL);
-    if (!st->nc_sess2) {
-        SETUP_FAIL_LOG;
-        return 1;
-    }
-    if (np2_glob_test_setup_sess_ctx(st->nc_sess2, modules)) {
-        SETUP_FAIL_LOG;
-        return 1;
-    }
+    if (flags & NP_GLOB_SETUP_OTHER_CLIENT) {
+        st->oc_sess = oc_connect_unix(st->socket_path);
+        if (!st->oc_sess) {
+            SETUP_FAIL_LOG;
+            return 1;
+        }
+    } else {
+        /* create NETCONF sessions, with a single context */
+        st->nc_sess2 = nc_connect_unix(st->socket_path, NULL);
+        if (!st->nc_sess2) {
+            SETUP_FAIL_LOG;
+            return 1;
+        }
+        if (np2_glob_test_setup_sess_ctx(st->nc_sess2, modules)) {
+            SETUP_FAIL_LOG;
+            return 1;
+        }
 
-    ly_ctx = (struct ly_ctx *)nc_session_get_ctx(st->nc_sess2);
-    st->nc_sess = nc_connect_unix(st->socket_path, ly_ctx);
-    if (!st->nc_sess) {
-        SETUP_FAIL_LOG;
-        return 1;
+        ly_ctx = (struct ly_ctx *)nc_session_get_ctx(st->nc_sess2);
+        st->nc_sess = nc_connect_unix(st->socket_path, ly_ctx);
+        if (!st->nc_sess) {
+            SETUP_FAIL_LOG;
+            return 1;
+        }
     }
 
     return 0;
@@ -510,6 +519,8 @@ np2_glob_test_teardown(void **state, const char **modules)
     /* release context */
     sr_release_context(st->conn);
 
+    oc_session_free(st->oc_sess);
+
 #ifdef NETOPEER2_LIB
     if (np2_server_test_stop()) {
         printf("np2_server_test_stop() failed\n");
diff --git a/tests/np2_test.h b/tests/np2_test.h
index 79980086..15465298 100644
--- a/tests/np2_test.h
+++ b/tests/np2_test.h
@@ -45,6 +45,7 @@ struct np2_test {
     char *str;
     char *path;
     uint32_t ntf_id;
+    struct np_other_client *oc_sess;
 };
 
 #define SETUP_FAIL_LOG \
@@ -299,7 +300,8 @@ void np2_glob_test_setup_test_name(char *buf);
 
 int np2_glob_test_setup_env(const char *test_name);
 
-int np2_glob_test_setup_server(void **state, const char *test_name, const char **modules);
+#define NP_GLOB_SETUP_OTHER_CLIENT 0x1
+int np2_glob_test_setup_server(void **state, const char *test_name, const char **modules, uint32_t flags);
 
 int np2_glob_test_teardown_notif(const char *test_name);
 
diff --git a/tests/test_candidate.c b/tests/test_candidate.c
index f066f52f..aebb749e 100644
--- a/tests/test_candidate.c
+++ b/tests/test_candidate.c
@@ -47,7 +47,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
     st = *state;
 
diff --git a/tests/test_confirmed_commit.c b/tests/test_confirmed_commit.c
index 52f15a00..02e55e30 100644
--- a/tests/test_confirmed_commit.c
+++ b/tests/test_confirmed_commit.c
@@ -123,7 +123,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
     st = *state;
 
diff --git a/tests/test_edit.c b/tests/test_edit.c
index a67c1a98..4ef2ad84 100644
--- a/tests/test_edit.c
+++ b/tests/test_edit.c
@@ -51,7 +51,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
 
     /* setup NACM */
diff --git a/tests/test_error.c b/tests/test_error.c
index b5023996..18398133 100644
--- a/tests/test_error.c
+++ b/tests/test_error.c
@@ -46,7 +46,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
 
     /* setup NACM */
diff --git a/tests/test_filter.c b/tests/test_filter.c
index 6d5474b3..ccc0254b 100644
--- a/tests/test_filter.c
+++ b/tests/test_filter.c
@@ -317,7 +317,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
     st = *state;
 
diff --git a/tests/test_nacm.c b/tests/test_nacm.c
index 12338fdc..d16b9584 100644
--- a/tests/test_nacm.c
+++ b/tests/test_nacm.c
@@ -52,7 +52,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
     st = *state;
 
diff --git a/tests/test_other_client.c b/tests/test_other_client.c
new file mode 100644
index 00000000..4e5da18c
--- /dev/null
+++ b/tests/test_other_client.c
@@ -0,0 +1,431 @@
+/**
+ * @file test_other_client.h
+ * @author Adam Piecek <piecek@cesnet.cz>
+ * @brief An alternative client which communicate with NETCONF server.
+ *
+ * @copyright
+ * Copyright (c) 2019 - 2024 Deutsche Telekom AG.
+ * Copyright (c) 2017 - 2024 CESNET, z.s.p.o.
+ *
+ * This source code is licensed under BSD 3-Clause License (the "License").
+ * You may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://opensource.org/licenses/BSD-3-Clause
+ */
+
+#define _GNU_SOURCE
+
+#include <setjmp.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <cmocka.h>
+#include <libyang/libyang.h>
+
+#include "np2_other_client.h"
+#include "np2_test.h"
+#include "np2_test_config.h"
+
+static int
+local_setup(void **state)
+{
+    char test_name[256];
+    const char *modules[] = {NP_TEST_MODULE_DIR "/errors.yang", NULL};
+    int rc;
+
+    /* get test name */
+    np2_glob_test_setup_test_name(test_name);
+
+    /* setup environment necessary for installing module */
+    rc = np2_glob_test_setup_env(test_name);
+    assert_int_equal(rc, 0);
+
+    /* setup netopeer2 server */
+    rc = np2_glob_test_setup_server(state, test_name, modules, NP_GLOB_SETUP_OTHER_CLIENT);
+    assert_int_equal(rc, 0);
+
+    /* setup NACM */
+    rc = np2_glob_test_setup_nacm(state);
+    assert_int_equal(rc, 0);
+
+    return 0;
+}
+
+static int
+local_teardown(void **state)
+{
+    const char *modules[] = {"errors", NULL};
+
+    /* close netopeer2 server */
+    if (*state) {
+        return np2_glob_test_teardown(state, modules);
+    }
+
+    return 0;
+}
+
+static void
+test_message_id(void **state)
+{
+    int rc;
+    char *msg, *exp;
+    struct np2_test *st = *state;
+    struct np_other_client *sess = st->oc_sess;
+
+    /* send malformed message */
+    asprintf(&msg,
+            "<rpc xmlns=\"urn&ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\">"
+            "  <discard-changes/>"
+            "</rpc>", sess->msgid);
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    free(msg);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+
+    /* then send valid message */
+    asprintf(&msg,
+            "<rpc xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\">"
+            "  <discard-changes/>"
+            "</rpc>", sess->msgid);
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    free(msg);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+    asprintf(&exp, "<rpc-reply xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\""
+            " message-id=\"%" PRIu64 "\"><ok/></rpc-reply>", sess->msgid);
+    assert_string_equal(msg, exp);
+    free(exp);
+}
+
+static void
+test_missing_attribute(void **state)
+{
+    int rc;
+    char *msg, *exp;
+    struct np2_test *st = *state;
+    struct np_other_client *sess = st->oc_sess;
+
+    /* missing attribute 'message-id' in the rpc layer */
+    msg =
+            "<rpc xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\">"
+            "  <discard-changes/>"
+            "</rpc>";
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+    assert_string_equal(msg,
+            "<rpc-reply xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\"><rpc-error>"
+            "<error-type>rpc</error-type>"
+            "<error-tag>missing-attribute</error-tag><error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">An expected attribute is missing.</error-message>"
+            "<error-info><bad-attribute>message-id</bad-attribute>"
+            "<bad-element>rpc</bad-element>"
+            "</error-info></rpc-error></rpc-reply>");
+
+    /* missing attribute 'xmlns' in the rpc layer */
+    asprintf(&msg,
+            "<rpc message-id=\"%" PRIu64 "\">"
+            "  <discard-changes/>"
+            "</rpc>", sess->msgid);
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    free(msg);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+    assert_string_equal(msg,
+            "<rpc-reply xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\"><rpc-error>"
+            "<error-type>rpc</error-type>"
+            "<error-tag>missing-attribute</error-tag><error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">An expected attribute is missing.</error-message>"
+            "<error-info><bad-attribute>xmlns</bad-attribute>"
+            "<bad-element>rpc</bad-element></error-info>"
+            "</rpc-error></rpc-reply>");
+
+    /* missing attribute 'select' in the protocol layer */
+    asprintf(&msg,
+            "<rpc xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\">"
+            "  <get-config>"
+            "    <source>"
+            "      <running/>"
+            "    </source>"
+            "    <filter type=\"xpath\"/>"
+            "  </get-config>"
+            "</rpc>", sess->msgid);
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    free(msg);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+    asprintf(&exp,
+            "<rpc-reply xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\"><rpc-error>"
+            "<error-type>protocol</error-type>"
+            "<error-tag>missing-attribute</error-tag>"
+            "<error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">Missing \"select\" attribute</error-message>"
+            "<error-info><bad-element>filter</bad-element></error-info></rpc-error></rpc-reply>", sess->msgid);
+    assert_string_equal(msg, exp);
+    free(exp);
+}
+
+static void
+test_unknown_attribute(void **state)
+{
+    int rc;
+    char *msg, *exp;
+    struct np2_test *st = *state;
+    struct np_other_client *sess = st->oc_sess;
+
+    /* unknown attribute 'att' in the rpc layer,
+     * but in this case it's ok because rfc 6241 is benevolent towards attributes.
+     */
+    asprintf(&msg,
+            "<rpc att=\"4\" xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\">"
+            "  <discard-changes/>"
+            "</rpc>", sess->msgid);
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    free(msg);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+    asprintf(&exp,
+            "<rpc-reply xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" att=\"4\" message-id=\"%" PRIu64 "\">"
+            "<ok/></rpc-reply>", sess->msgid);
+    assert_string_equal(msg, exp);
+    free(exp);
+
+    /* unknown attribute 'att' in the protocol layer: annotation not found */
+    asprintf(&msg,
+            "<rpc xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\">"
+            "  <discard-changes xmlns:el=\"urn:ietf:params:xml:ns:netconf:base:1.0\" el:att=\"4\"/>"
+            "</rpc>", sess->msgid);
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    free(msg);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+    asprintf(&exp,
+            "<rpc-reply xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\"><rpc-error>"
+            "<error-type>protocol</error-type>"
+            "<error-tag>unknown-attribute</error-tag>"
+            "<error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">Annotation definition for attribute \"ietf-netconf:att\" not found.</error-message>"
+            "<error-info><bad-attribute>att</bad-attribute>"
+            "<bad-element>discard-changes</bad-element></error-info>"
+            "</rpc-error></rpc-reply>", sess->msgid);
+    assert_string_equal(msg, exp);
+    free(exp);
+
+    /* unknown attribute 'att' in the protocol layer: missing prefix */
+    asprintf(&msg,
+            "<rpc xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\">"
+            "  <discard-changes att=\"4\"/>"
+            "</rpc>", sess->msgid);
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    free(msg);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+    asprintf(&exp,
+            "<rpc-reply xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\"><rpc-error>"
+            "<error-type>protocol</error-type>"
+            "<error-tag>unknown-attribute</error-tag>"
+            "<error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">Missing mandatory prefix for XML metadata \"att\".</error-message>"
+            "<error-info><bad-attribute>att</bad-attribute>"
+            "<bad-element>discard-changes</bad-element></error-info>"
+            "</rpc-error></rpc-reply>", sess->msgid);
+    assert_string_equal(msg, exp);
+    free(exp);
+
+    /* unknown attribute 'att' in the protocol layer: unknown XML prefix */
+    asprintf(&msg,
+            "<rpc xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\">"
+            "  <discard-changes el:att=\"4\"/>"
+            "</rpc>", sess->msgid);
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    free(msg);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+    asprintf(&exp,
+            "<rpc-reply xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\"><rpc-error>"
+            "<error-type>protocol</error-type>"
+            "<error-tag>unknown-attribute</error-tag>"
+            "<error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">Unknown XML prefix \"el\" at attribute \"att\".</error-message>"
+            "<error-info><bad-attribute>att</bad-attribute>"
+            "<bad-element>discard-changes</bad-element></error-info>"
+            "</rpc-error></rpc-reply>", sess->msgid);
+    assert_string_equal(msg, exp);
+    free(exp);
+}
+
+static void
+test_missing_element(void **state)
+{
+    int rc;
+    char *msg, *exp;
+    struct np2_test *st = *state;
+    struct np_other_client *sess = st->oc_sess;
+
+    /* missing element in 'edit-content' in the protocol layer: missing mandatory node in the choice-stmt */
+    asprintf(&msg,
+            "<rpc xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\">"
+            "  <edit-data xmlns=\"urn:ietf:params:xml:ns:yang:ietf-netconf-nmda\">"
+            "    <datastore xmlns:ds=\"urn:ietf:params:xml:ns:yang:ietf-datastores\">ds:running</datastore>"
+            "  </edit-data>"
+            "</rpc>", sess->msgid);
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    free(msg);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+    asprintf(&exp,
+            "<rpc-reply xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\"><rpc-error>"
+            "<error-type>protocol</error-type>"
+            "<error-tag>missing-element</error-tag>"
+            "<error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">Mandatory choice \"edit-content\" data do not exist."
+            " (path \"/ietf-netconf-nmda:edit-data\")</error-message>"
+            "<error-info><bad-element>edit-content</bad-element></error-info>"
+            "</rpc-error>"
+            "<rpc-error>"
+            "<error-type>application</error-type>"
+            "<error-tag>operation-failed</error-tag>"
+            "<error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">RPC input validation failed.</error-message>"
+            "</rpc-error></rpc-reply>", sess->msgid);
+    assert_string_equal(msg, exp);
+    free(exp);
+
+    /* missing element 'identifier' in the protocol layer */
+    asprintf(&msg,
+            "<rpc xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\">"
+            "  <get-schema xmlns=\"urn:ietf:params:xml:ns:yang:ietf-netconf-monitoring\"/>"
+            "</rpc>", sess->msgid);
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    free(msg);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+    asprintf(&exp,
+            "<rpc-reply xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\"><rpc-error>"
+            "<error-type>protocol</error-type>"
+            "<error-tag>missing-element</error-tag>"
+            "<error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">Mandatory node \"identifier\" instance does not exist."
+            " (path \"/ietf-netconf-monitoring:get-schema\")</error-message>"
+            "<error-info><bad-element>identifier</bad-element></error-info>"
+            "</rpc-error>"
+            "<rpc-error>"
+            "<error-type>application</error-type>"
+            "<error-tag>operation-failed</error-tag>"
+            "<error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">RPC input validation failed.</error-message>"
+            "</rpc-error></rpc-reply>", sess->msgid);
+    assert_string_equal(msg, exp);
+    free(exp);
+
+    /* missing element in 'config-choice' in the application layer: missing mandatory node in the choice-stmt */
+    asprintf(&msg,
+            "<rpc xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\">"
+            "  <get-config>"
+            "    <source/>"
+            "  </get-config>"
+            "</rpc>", sess->msgid);
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    free(msg);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+    asprintf(&exp,
+            "<rpc-reply xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\"><rpc-error>"
+            "<error-type>application</error-type>"
+            "<error-tag>missing-element</error-tag>"
+            "<error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">Mandatory choice \"config-source\" data do not exist."
+            " (path \"/ietf-netconf:get-config/source\")</error-message>"
+            "<error-info><bad-element>config-source</bad-element></error-info>"
+            "</rpc-error>"
+            "<rpc-error>"
+            "<error-type>application</error-type>"
+            "<error-tag>operation-failed</error-tag>"
+            "<error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">RPC input validation failed.</error-message>"
+            "</rpc-error></rpc-reply>", sess->msgid);
+    assert_string_equal(msg, exp);
+    free(exp);
+}
+
+static void
+test_malformed_message(void **state)
+{
+    int rc;
+    char *msg, *exp;
+    struct np2_test *st = *state;
+    struct np_other_client *sess = st->oc_sess;
+
+    /* malformed-message xmlns in the rpc layer */
+    asprintf(&msg,
+            "<rpc xmlns=\"urn&ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\">"
+            "  <discard-changes/>"
+            "</rpc>", sess->msgid);
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    free(msg);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+    assert_string_equal(msg,
+            "<rpc-reply xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\">"
+            "<rpc-error>"
+            "<error-type>rpc</error-type>"
+            "<error-tag>malformed-message</error-tag>"
+            "<error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">A message could not be handled because it failed to be parsed correctly.</error-message>"
+            "</rpc-error></rpc-reply>");
+
+    /* malformed-message in the non-rpc layer */
+    asprintf(&msg,
+            "<rpc xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\">"
+            "  <discard-cha&ges/>"
+            "</rpc>", sess->msgid);
+    rc = oc_send_msg(sess, msg);
+    assert_int_equal(rc, 0);
+    free(msg);
+    rc = oc_recv_msg(sess, &msg);
+    assert_int_equal(rc, 0);
+    asprintf(&exp,
+            "<rpc-reply xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" message-id=\"%" PRIu64 "\">"
+            "<rpc-error>"
+            "<error-type>rpc</error-type>"
+            "<error-tag>malformed-message</error-tag>"
+            "<error-severity>error</error-severity>"
+            "<error-message xml:lang=\"en\">Invalid character sequence \"&amp;ges/&gt;&lt;/rpc&gt;\","
+            " expected element tag end ('&gt;' or '/&gt;') or an attribute.</error-message>"
+            "</rpc-error></rpc-reply>", sess->msgid);
+    assert_string_equal(msg, exp);
+    free(exp);
+}
+
+int
+main(int argc, char **argv)
+{
+    const struct CMUnitTest tests[] = {
+        cmocka_unit_test(test_message_id),
+        cmocka_unit_test(test_missing_attribute),
+        cmocka_unit_test(test_unknown_attribute),
+        cmocka_unit_test(test_missing_element),
+        cmocka_unit_test(test_malformed_message),
+    };
+
+    nc_verbosity(NC_VERB_WARNING);
+    parse_arg(argc, argv);
+    return cmocka_run_group_tests(tests, local_setup, local_teardown);
+}
diff --git a/tests/test_parallel_sessions.c b/tests/test_parallel_sessions.c
index 56507fcb..82ff4f08 100644
--- a/tests/test_parallel_sessions.c
+++ b/tests/test_parallel_sessions.c
@@ -48,7 +48,7 @@ local_setup(void **state)
     rc = np2_glob_test_setup_env(test_name);
     assert_int_equal(rc, 0);
 
-    return np2_glob_test_setup_server(state, test_name, NULL);
+    return np2_glob_test_setup_server(state, test_name, NULL, 0);
 }
 
 static int
diff --git a/tests/test_rpc.c b/tests/test_rpc.c
index c8056799..9d96b6ff 100644
--- a/tests/test_rpc.c
+++ b/tests/test_rpc.c
@@ -51,7 +51,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
 
     /* setup NACM */
diff --git a/tests/test_sub_ntf.c b/tests/test_sub_ntf.c
index eea618ed..b4c92e80 100644
--- a/tests/test_sub_ntf.c
+++ b/tests/test_sub_ntf.c
@@ -49,7 +49,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
     st = *state;
 
diff --git a/tests/test_sub_ntf_advanced.c b/tests/test_sub_ntf_advanced.c
index 6f02ebb4..cc862a0d 100644
--- a/tests/test_sub_ntf_advanced.c
+++ b/tests/test_sub_ntf_advanced.c
@@ -50,7 +50,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
     st = *state;
 
diff --git a/tests/test_sub_ntf_filter.c b/tests/test_sub_ntf_filter.c
index b1ffb1c8..ca76cfe4 100644
--- a/tests/test_sub_ntf_filter.c
+++ b/tests/test_sub_ntf_filter.c
@@ -49,7 +49,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
     st = *state;
 
diff --git a/tests/test_subscribe_filter.c b/tests/test_subscribe_filter.c
index 7dc9ecc0..4e662167 100644
--- a/tests/test_subscribe_filter.c
+++ b/tests/test_subscribe_filter.c
@@ -88,7 +88,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
     st = *state;
 
diff --git a/tests/test_subscribe_param.c b/tests/test_subscribe_param.c
index 952fd03f..42959621 100644
--- a/tests/test_subscribe_param.c
+++ b/tests/test_subscribe_param.c
@@ -69,7 +69,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
     st = *state;
 
diff --git a/tests/test_url.c b/tests/test_url.c
index e0c5132d..47b521bd 100644
--- a/tests/test_url.c
+++ b/tests/test_url.c
@@ -82,7 +82,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
 
     /* setup NACM */
diff --git a/tests/test_with_defaults.c b/tests/test_with_defaults.c
index 7f8fb881..353bac2b 100644
--- a/tests/test_with_defaults.c
+++ b/tests/test_with_defaults.c
@@ -46,7 +46,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
 
     return 0;
diff --git a/tests/test_yang_push.c b/tests/test_yang_push.c
index 036a3c38..a98988ee 100644
--- a/tests/test_yang_push.c
+++ b/tests/test_yang_push.c
@@ -49,7 +49,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
     st = *state;
 
diff --git a/tests/test_yang_push_advanced.c b/tests/test_yang_push_advanced.c
index 92bed2da..0f4ee4cb 100644
--- a/tests/test_yang_push_advanced.c
+++ b/tests/test_yang_push_advanced.c
@@ -49,7 +49,7 @@ local_setup(void **state)
     assert_int_equal(rc, 0);
 
     /* setup netopeer2 server */
-    rc = np2_glob_test_setup_server(state, test_name, modules);
+    rc = np2_glob_test_setup_server(state, test_name, modules, 0);
     assert_int_equal(rc, 0);
     st = *state;