diff --git a/src/monitor/replication_state.c b/src/monitor/replication_state.c
index b72e3404e..f1191176e 100644
--- a/src/monitor/replication_state.c
+++ b/src/monitor/replication_state.c
@@ -39,8 +39,15 @@ static bool IsReplicationStateName(char *name, ReplicationState replicationState
 Oid
 ReplicationStateTypeOid(void)
 {
+/* new String type in version 15devel  */
+#if (PG_VERSION_NUM >= 150000)
+	String *schemaName = makeString(AUTO_FAILOVER_SCHEMA_NAME);
+	String *typeName = makeString(REPLICATION_STATE_TYPE_NAME);
+#else
 	Value *schemaName = makeString(AUTO_FAILOVER_SCHEMA_NAME);
 	Value *typeName = makeString(REPLICATION_STATE_TYPE_NAME);
+#endif
+
 	List *enumTypeNameList = list_make2(schemaName, typeName);
 	TypeName *enumTypeName = makeTypeNameFromNameList(enumTypeNameList);
 	Oid enumTypeOid = typenameTypeId(NULL, enumTypeName);
diff --git a/src/monitor/version_compat.h b/src/monitor/version_compat.h
index 91391a289..f50f32881 100644
--- a/src/monitor/version_compat.h
+++ b/src/monitor/version_compat.h
@@ -14,8 +14,8 @@
 
 #include "postgres.h"
 
-/* we support Postgres versions 10, 11, 12, 13, and 14. */
-#if (PG_VERSION_NUM < 100000 || PG_VERSION_NUM >= 150000)
+/* we support Postgres versions 10, 11, 12, 13, and 14. And 15devel. */
+#if (PG_VERSION_NUM < 100000 || PG_VERSION_NUM >= 160000)
 #error "Unknown or unsupported postgresql version"
 #endif