Index: ibus-hangul-1.5.4/src/engine.c
===================================================================
--- ibus-hangul-1.5.4.orig/src/engine.c
+++ ibus-hangul-1.5.4/src/engine.c
@@ -1577,7 +1577,11 @@ ibus_hangul_engine_process_key_event (IB
      *
      * See: https://github.com/choehwanjin/ibus-hangul/issues/40
      */
-    if (use_event_forwarding) {
+    if (use_event_forwarding
+#if IBUS_CHECK_VERSION(1, 5, 25)
+        && (hangul->caps & IBUS_CAP_SYNC_PROCESS_KEY_V2)
+#endif
+        ) {
         if (!retval) {
             ibus_engine_forward_key_event (engine, orig_keyval, keycode, modifiers);
         }