diff --git a/src/libmongoc/tests/unified/entity-map.c b/src/libmongoc/tests/unified/entity-map.c
index e12d25c384..ad4f50b110 100644
--- a/src/libmongoc/tests/unified/entity-map.c
+++ b/src/libmongoc/tests/unified/entity-map.c
@@ -1651,7 +1651,10 @@ session_opts_new (bson_t *bson, bson_error_t *error)
 }
 
 entity_t *
-entity_session_new (entity_map_t *entity_map, bson_t *bson, bson_error_t *error)
+entity_session_new (entity_map_t *entity_map,
+                    bson_t *bson,
+                    const bson_t *cluster_time_after_initial_data,
+                    bson_error_t *error)
 {
    bson_parser_t *parser = NULL;
    entity_t *entity = NULL;
@@ -1691,6 +1694,9 @@ entity_session_new (entity_map_t *entity_map, bson_t *bson, bson_error_t *error)
    if (!session) {
       goto done;
    }
+   if (cluster_time_after_initial_data) {
+      mongoc_client_session_advance_cluster_time (session, cluster_time_after_initial_data);
+   }
    entity->value = session;
    /* Ending a session destroys the session object.
     * After a session is ended, match assertions may be made on the lsid.
@@ -1785,7 +1791,10 @@ entity_bucket_new (entity_map_t *entity_map, bson_t *bson, bson_error_t *error)
  * object immediately.
  */
 bool
-entity_map_create (entity_map_t *entity_map, bson_t *bson, bson_error_t *error)
+entity_map_create (entity_map_t *entity_map,
+                   bson_t *bson,
+                   const bson_t *cluster_time_after_initial_data,
+                   bson_error_t *error)
 {
    bson_iter_t iter;
    const char *entity_type;
@@ -1816,7 +1825,7 @@ entity_map_create (entity_map_t *entity_map, bson_t *bson, bson_error_t *error)
    } else if (0 == strcmp (entity_type, "collection")) {
       entity = entity_collection_new (entity_map, &entity_bson, error);
    } else if (0 == strcmp (entity_type, "session")) {
-      entity = entity_session_new (entity_map, &entity_bson, error);
+      entity = entity_session_new (entity_map, &entity_bson, cluster_time_after_initial_data, error);
    } else if (0 == strcmp (entity_type, "bucket")) {
       entity = entity_bucket_new (entity_map, &entity_bson, error);
    } else {
diff --git a/src/libmongoc/tests/unified/entity-map.h b/src/libmongoc/tests/unified/entity-map.h
index f01bc1b690..dd696dd2e8 100644
--- a/src/libmongoc/tests/unified/entity-map.h
+++ b/src/libmongoc/tests/unified/entity-map.h
@@ -96,7 +96,7 @@ entity_map_destroy (entity_map_t *em);
 /* Creates an entry in the entity map based on what is specified in @bson.
  */
 bool
-entity_map_create (entity_map_t *em, bson_t *bson, bson_error_t *error);
+entity_map_create (entity_map_t *em, bson_t *bson, const bson_t *cluster_time_after_initial_data, bson_error_t *error);
 
 /* Steals ownership of changestream. */
 bool
diff --git a/src/libmongoc/tests/unified/operation.c b/src/libmongoc/tests/unified/operation.c
index fda829dc18..cfd9cc4498 100644
--- a/src/libmongoc/tests/unified/operation.c
+++ b/src/libmongoc/tests/unified/operation.c
@@ -3833,7 +3833,7 @@ operation_create_entities (test_t *test, operation_t *op, result_t *result, bson
    {
       bson_t entity;
       bson_iter_bson (&entity_iter, &entity);
-      bool create_ret = entity_map_create (test->entity_map, &entity, error);
+      bool create_ret = entity_map_create (test->entity_map, &entity, test->cluster_time_after_initial_data, error);
       bson_destroy (&entity);
       if (!create_ret) {
          goto done;
diff --git a/src/libmongoc/tests/unified/runner.c b/src/libmongoc/tests/unified/runner.c
index e2d302ee42..7959105198 100644
--- a/src/libmongoc/tests/unified/runner.c
+++ b/src/libmongoc/tests/unified/runner.c
@@ -532,6 +532,7 @@ test_destroy (test_t *test)
    bson_destroy (test->run_on_requirements);
    bson_free (test->description);
    bson_free (test->skip_reason);
+   bson_destroy (test->cluster_time_after_initial_data);
    bson_free (test);
 }
 
@@ -866,8 +867,27 @@ test_setup_initial_data (test_t *test, bson_error_t *error)
    test_file = test->test_file;
    test_runner = test_file->test_runner;
 
+   mongoc_client_session_t *sess = mongoc_client_start_session (test_runner->internal_client, NULL, error);
+   if (sess == NULL) {
+      return false;
+   }
+
    if (!test_file->initial_data) {
-      return true;
+      // Send a "ping" command with the session to get a cluster time.
+      bson_t opts = BSON_INITIALIZER;
+      bool ok = mongoc_client_session_append (sess, &opts, error);
+      ok = ok && mongoc_client_command_with_opts (
+                    test_runner->internal_client, "db", tmp_bson ("{'ping': 1}"), NULL, &opts, NULL, error);
+      if (ok) {
+         // Check for cluster time (not available on standalone).
+         const bson_t *ct = mongoc_client_session_get_cluster_time (sess);
+         if (ct) {
+            test->cluster_time_after_initial_data = bson_copy (ct);
+         }
+      }
+      mongoc_client_session_destroy (sess);
+      bson_destroy (&opts);
+      return ok;
    }
 
    BSON_FOREACH (test_file->initial_data, initial_data_iter)
@@ -899,6 +919,9 @@ test_setup_initial_data (test_t *test, bson_error_t *error)
       mongoc_write_concern_set_w (wc, MONGOC_WRITE_CONCERN_W_MAJORITY);
       bulk_opts = bson_new ();
       mongoc_write_concern_append (wc, bulk_opts);
+      if (!mongoc_client_session_append (sess, bulk_opts, error)) {
+         goto loopexit;
+      }
 
       /* Drop the collection. */
       /* Check if the server supports majority write concern on 'drop' and
@@ -913,6 +936,12 @@ test_setup_initial_data (test_t *test, bson_error_t *error)
          BSON_APPEND_INT32 (drop_opts, "serverId", 1);
          BSON_APPEND_INT32 (create_opts, "serverId", 1);
       }
+      if (!mongoc_client_session_append (sess, create_opts, error)) {
+         goto loopexit;
+      }
+      if (!mongoc_client_session_append (sess, drop_opts, error)) {
+         goto loopexit;
+      }
 
       coll = mongoc_client_get_collection (test_runner->internal_client, database_name, collection_name);
       if (!mongoc_collection_drop_with_opts (coll, drop_opts, error)) {
@@ -972,9 +1001,18 @@ test_setup_initial_data (test_t *test, bson_error_t *error)
       bson_parser_destroy (parser);
       mongoc_database_destroy (db);
       if (!ret) {
+         mongoc_client_session_destroy (sess);
          return false;
       }
    }
+
+   // Obtain cluster time to advance client sessions. See DRIVERS-2816.
+   // Check for cluster time (not available on standalone).
+   const bson_t *ct = mongoc_client_session_get_cluster_time (sess);
+   if (ct) {
+      test->cluster_time_after_initial_data = bson_copy (ct);
+   }
+   mongoc_client_session_destroy (sess);
    return true;
 }
 
@@ -1001,7 +1039,7 @@ test_create_entities (test_t *test, bson_error_t *error)
       bson_t entity_bson;
 
       bson_iter_bson (&iter, &entity_bson);
-      if (!entity_map_create (test->entity_map, &entity_bson, error)) {
+      if (!entity_map_create (test->entity_map, &entity_bson, test->cluster_time_after_initial_data, error)) {
          return false;
       }
    }
diff --git a/src/libmongoc/tests/unified/runner.h b/src/libmongoc/tests/unified/runner.h
index 5a3c59ad05..349b15540f 100644
--- a/src/libmongoc/tests/unified/runner.h
+++ b/src/libmongoc/tests/unified/runner.h
@@ -63,6 +63,7 @@ typedef struct {
    entity_map_t *entity_map;
    failpoint_t *failpoints;
    bool loop_operation_executed;
+   bson_t *cluster_time_after_initial_data;
 } test_t;
 
 /* Set server_id to 0 if the failpoint was not against a pinned mongos. */