diff --git a/collector.c b/collector.c
index 237061f..2fa80c3 100644
--- a/collector.c
+++ b/collector.c
@@ -220,7 +220,7 @@ send_history(History *observations, shm_mq_handle *mqh)
 	else
 		count = observations->index;
 
-	mq_result = shm_mq_send(mqh, sizeof(count), &count, false);
+	mq_result = shm_mq_send_compat(mqh, sizeof(count), &count, false, true);
 	if (mq_result == SHM_MQ_DETACHED)
 	{
 		ereport(WARNING,
@@ -230,10 +230,11 @@ send_history(History *observations, shm_mq_handle *mqh)
 	}
 	for (i = 0; i < count; i++)
 	{
-		mq_result = shm_mq_send(mqh,
+		mq_result = shm_mq_send_compat(mqh,
 								sizeof(HistoryItem),
 								&observations->items[i],
-								false);
+								false,
+								true);
 		if (mq_result == SHM_MQ_DETACHED)
 		{
 			ereport(WARNING,
@@ -255,7 +256,7 @@ send_profile(HTAB *profile_hash, shm_mq_handle *mqh)
 	Size			count = hash_get_num_entries(profile_hash);
 	shm_mq_result	mq_result;
 
-	mq_result = shm_mq_send(mqh, sizeof(count), &count, false);
+	mq_result = shm_mq_send_compat(mqh, sizeof(count), &count, false, true);
 	if (mq_result == SHM_MQ_DETACHED)
 	{
 		ereport(WARNING,
@@ -266,7 +267,8 @@ send_profile(HTAB *profile_hash, shm_mq_handle *mqh)
 	hash_seq_init(&scan_status, profile_hash);
 	while ((item = (ProfileItem *) hash_seq_search(&scan_status)) != NULL)
 	{
-		mq_result = shm_mq_send(mqh, sizeof(ProfileItem), item, false);
+		mq_result = shm_mq_send_compat(mqh, sizeof(ProfileItem), item, false,
+									   true);
 		if (mq_result == SHM_MQ_DETACHED)
 		{
 			hash_seq_term(&scan_status);
diff --git a/compat.c b/compat.c
index 249a53a..7004d7e 100644
--- a/compat.c
+++ b/compat.c
@@ -13,6 +13,17 @@ shm_mq_detach_compat(shm_mq_handle *mqh, shm_mq *mq)
 #endif
 }
 
+inline shm_mq_result
+shm_mq_send_compat(shm_mq_handle *mqh, Size nbytes, const void *data,
+				   bool nowait, bool force_flush)
+{
+#if PG_VERSION_NUM >= 150000
+	return shm_mq_send(mqh, nbytes, data, nowait, force_flush);
+#else
+	return shm_mq_send(mqh, nbytes, data, nowait);
+#endif
+}
+
 inline TupleDesc
 CreateTemplateTupleDescCompat(int nattrs, bool hasoid)
 {
diff --git a/pg_wait_sampling.h b/pg_wait_sampling.h
index 1001f6f..4c0ddac 100644
--- a/pg_wait_sampling.h
+++ b/pg_wait_sampling.h
@@ -84,6 +84,9 @@ extern void alloc_history(History *, int);
 extern void collector_main(Datum main_arg);
 
 extern void shm_mq_detach_compat(shm_mq_handle *mqh, shm_mq *mq);
+extern shm_mq_result shm_mq_send_compat(shm_mq_handle *mqh, Size nbytes,
+										const void *data, bool nowait,
+										bool force_flush);
 extern TupleDesc CreateTemplateTupleDescCompat(int nattrs, bool hasoid);
 
 #endif