diff --git a/servers/slapd/back-bdb/tools.c b/servers/slapd/back-bdb/tools.c
index 65d947b379..35e45f0383 100644
--- a/servers/slapd/back-bdb/tools.c
+++ b/servers/slapd/back-bdb/tools.c
@@ -1120,6 +1120,8 @@ bdb_tool_trickle_task( void *ctx, void *ptr )
 		env->memp_trickle( env, 30, &wrote );
 	}
 	ldap_pvt_thread_mutex_unlock( &bdb_tool_trickle_mutex );
+
+	return NULL;
 }
 
 static void *