diff --git a/modules/im/ximcp/imDefFlt.c b/modules/im/ximcp/imDefFlt.c
index 44cc6884..834b9db4 100644
--- a/modules/im/ximcp/imDefFlt.c
+++ b/modules/im/ximcp/imDefFlt.c
@@ -142,9 +142,9 @@ _XimProtoKeypressFilter(
 {
     Xim		im = (Xim)ic->core.im;
 
-    if (IS_FABRICATED(im)) {
+    if (_XimIsFabricatedSerial(im, ev->serial)) {
 	_XimPendingFilter(ic);
-	UNMARK_FABRICATED(im);
+	_XimUnfabricateSerial(im, ev->serial);
 	return NOTFILTERD;
     }
 
@@ -203,9 +203,9 @@ _XimProtoKeyreleaseFilter(
 {
     Xim		im = (Xim)ic->core.im;
 
-    if (IS_FABRICATED(im)) {
+    if (_XimIsFabricatedSerial(im, ev->serial)) {
 	_XimPendingFilter(ic);
-	UNMARK_FABRICATED(im);
+	_XimUnfabricateSerial(im, ev->serial);
 	return NOTFILTERD;
     }
 
diff --git a/modules/im/ximcp/imDefIm.c b/modules/im/ximcp/imDefIm.c
index fe4d18ba..ac7f1195 100644
--- a/modules/im/ximcp/imDefIm.c
+++ b/modules/im/ximcp/imDefIm.c
@@ -430,6 +430,7 @@ _XimPreConnect(
 	return False;
 
     im->private.proto.im_window = im_window;
+    im->private.proto.fabricated_serial = 0;
     return True;
 }
 
diff --git a/modules/im/ximcp/imDefLkup.c b/modules/im/ximcp/imDefLkup.c
index dd1adf53..5192e8c1 100644
--- a/modules/im/ximcp/imDefLkup.c
+++ b/modules/im/ximcp/imDefLkup.c
@@ -341,6 +341,54 @@ _XimForwardEvent(
     return _XimForwardEventCore(ic, ev, sync);
 }
 
+Bool
+_XimFabricateSerial(
+    Xim			 im,
+    unsigned long	 serial)
+{
+    if (!serial)
+	return False;
+    if (serial == im->private.proto.fabricated_serial) {
+	fprintf(stderr, "%s,%d: The key event is already fabricated.\n", __FILE__, __LINE__);
+	return False;
+    }
+    if (im->private.proto.fabricated_serial)
+	fprintf(stderr, "%s,%d: Tried to fabricate a wrong key event.\n", __FILE__, __LINE__);
+
+    MARK_FABRICATED(im);
+    im->private.proto.fabricated_serial = serial;
+    return True;
+}
+
+Bool
+_XimUnfabricateSerial(
+    Xim			 im,
+    unsigned long	 serial)
+{
+    if (!serial)
+	return False;
+    if (!im->private.proto.fabricated_serial) {
+	fprintf(stderr, "%s,%d: The key event is already unfabricated.\n", __FILE__, __LINE__);
+	return False;
+    }
+    if (serial != im->private.proto.fabricated_serial)
+	fprintf(stderr, "%s,%d: Tried to unfabricate a wrong key event.\n", __FILE__, __LINE__);
+
+    im->private.proto.fabricated_serial = 0;
+    UNMARK_FABRICATED(im);
+    return True;
+}
+
+Bool
+_XimIsFabricatedSerial(
+    Xim			 im,
+    unsigned long	 serial)
+{
+    if (!serial)
+	return False;
+    return (serial == im->private.proto.fabricated_serial);
+}
+
 static void
 _XimProcEvent(
     Display		*d,
@@ -355,7 +403,7 @@ _XimProcEvent(
     ev->xany.serial |= serial << 16;
     ev->xany.send_event = False;
     ev->xany.display = d;
-    MARK_FABRICATED(ic->core.im);
+    _XimFabricateSerial((Xim)ic->core.im, ev->xany.serial);
     return;
 }
 
@@ -704,10 +752,6 @@ _XimCommitRecv(
 
     (void)_XimRespSyncReply(ic, flag);
 
-    if (ic->private.proto.registed_filter_event
-	& (KEYPRESS_MASK | KEYRELEASE_MASK))
-	    MARK_FABRICATED(im);
-
     bzero(&ev, sizeof(ev));	/* uninitialized : found when running kterm under valgrind */
 
     ev.type = KeyPress;
@@ -719,6 +763,10 @@ _XimCommitRecv(
 
     ev.time = 0L;
     ev.serial = LastKnownRequestProcessed(im->core.display);
+
+    if (ic->private.proto.registed_filter_event
+	& (KEYPRESS_MASK | KEYRELEASE_MASK))
+	    _XimFabricateSerial(im, ev.serial);
     /* FIXME :
        I wish there were COMMENTs (!) about the data passed around.
     */
diff --git a/src/xlibi18n/XimintP.h b/src/xlibi18n/XimintP.h
index 674da029..2a51e2ed 100644
--- a/src/xlibi18n/XimintP.h
+++ b/src/xlibi18n/XimintP.h
@@ -149,6 +149,8 @@ typedef struct _XimProtoPrivateRec {
     XimTransRegDispatcher	 register_dispatcher;
     XimTransCallDispatcher	 call_dispatcher;
     XPointer			 spec;
+
+    unsigned long                fabricated_serial;
 } XimProtoPrivateRec;
 
 /*
@@ -307,4 +309,19 @@ typedef struct _XicProtoPrivateRec {
 #define XIM_MAXIMNAMELEN 64
 #define XIM_MAXLCNAMELEN 64
 
+Bool
+_XimFabricateSerial(
+    Xim                  im,
+    unsigned long        serial);
+
+Bool
+_XimUnfabricateSerial(
+    Xim                  im,
+    unsigned long        serial);
+
+Bool
+_XimIsFabricatedSerial(
+    Xim                  im,
+    unsigned long        serial);
+
 #endif /* _XIMINTP_H */