diff --git a/.gitignore b/.gitignore
index 0bd19f8..08f721f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,6 @@
 *.so
 *.o
 *.bc
-*.gc*
\ No newline at end of file
+*.gc*
+/log/
+/tmp_check/
diff --git a/Makefile b/Makefile
index c589f72..db70be3 100644
--- a/Makefile
+++ b/Makefile
@@ -2,6 +2,9 @@ MODULE_big = pgotel
 
 EXTENSION = pgotel
 
+REGRESS = pgotel
+REGRESS_OPTS = --temp-instance=tmp_check
+
 DATA = pgotel--1.0.sql
 OBJS = pgotel.o
 PGFILEDESC = "pgotel - POC to interact with OpenTelemetry"
diff --git a/expected/pgotel.out b/expected/pgotel.out
new file mode 100644
index 0000000..80cb59a
--- /dev/null
+++ b/expected/pgotel.out
@@ -0,0 +1,19 @@
+CREATE EXTENSION pgotel;
+SELECT pgotel_counter('foo', -1);
+ERROR:  counter value cannot be negative
+SELECT pgotel_counter('foo', 0, '{}');
+ERROR:  invalid labels JSONB
+SELECT pgotel_counter('foo', 0, NULL);
+ERROR:  labels cannot be NULL
+SELECT pgotel_counter('foo', NULL);
+ERROR:  counter value cannot be negative
+SELECT pgotel_counter(NULL, 0);
+ERROR:  counter name cannot be NULL
+SELECT pgotel_counter(NULL, NULL);
+ERROR:  counter name cannot be NULL
+SELECT pgotel_counter('foo', 0, '{"dbname": "foo", "schemaname": "bar", "relname": "baz"}');
+ pgotel_counter 
+----------------
+ 
+(1 row)
+
diff --git a/pgotel.cpp b/pgotel.cpp
index ff455c6..19754a9 100644
--- a/pgotel.cpp
+++ b/pgotel.cpp
@@ -118,7 +118,7 @@ Datum
 pgotel_counter(PG_FUNCTION_ARGS)
 {
 	char *counter_name = PG_ARGISNULL(0) ? NULL : text_to_cstring(PG_GETARG_TEXT_PP(0));
-	float8 value = PG_ARGISNULL(0) ? -1 : PG_GETARG_FLOAT8(1);
+	float8 value = PG_ARGISNULL(1) ? -1 : PG_GETARG_FLOAT8(1);
 	Jsonb *labels = PG_ARGISNULL(2) ? NULL : PG_GETARG_JSONB_P(2);
 	std::map<std::string, std::string> labels_map;
 
@@ -131,6 +131,9 @@ pgotel_counter(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("counter value cannot be negative")));
 
+	if (labels == NULL && PG_NARGS() == 3)
+		ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("labels cannot be NULL")));
+
 	/* iterate over the labels JSONB to include key/values to the C++ map data structure */
 	if (labels != NULL)
 	{
@@ -153,6 +156,11 @@ pgotel_counter(PG_FUNCTION_ARGS)
 		}
 	}
 
+	elog(DEBUG1, "labels_map size: %d", (int) labels_map.size());
+	if (labels != NULL && (int) labels_map.size() == 0)
+		ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid labels JSONB")));
+
+	/* Send the counter to the OTEL-Collector */
 	pgotel::counter(counter_name, value, labels_map);
 
 	PG_RETURN_NULL();
diff --git a/sql/pgotel.sql b/sql/pgotel.sql
new file mode 100644
index 0000000..8df6a91
--- /dev/null
+++ b/sql/pgotel.sql
@@ -0,0 +1,9 @@
+CREATE EXTENSION pgotel;
+
+SELECT pgotel_counter('foo', -1);
+SELECT pgotel_counter('foo', 0, '{}');
+SELECT pgotel_counter('foo', 0, NULL);
+SELECT pgotel_counter('foo', NULL);
+SELECT pgotel_counter(NULL, 0);
+SELECT pgotel_counter(NULL, NULL);
+SELECT pgotel_counter('foo', 0, '{"dbname": "foo", "schemaname": "bar", "relname": "baz"}');
\ No newline at end of file