diff --git a/Xi/exevents.c b/Xi/exevents.c
index 98c28851c..2e9e8267f 100644
--- a/Xi/exevents.c
+++ b/Xi/exevents.c
@@ -126,6 +126,9 @@ ProcessOtherEvent(xEventPtr xE, DeviceIntPtr device, int count)
     ValuatorClassPtr v = device->valuator;
     deviceValuator *xV = (deviceValuator *) xE;
 
+    if (grab && grab->coreGrab && !device->deviceGrab.fromPassiveGrab)
+        return;
+
     if (xE->u.u.type != DeviceValuator && xE->u.u.type != GenericEvent) {
         DeviceIntPtr mouse = NULL, kbd = NULL;
 	GetSpritePosition(device, &rootX, &rootY);
diff --git a/dix/events.c b/dix/events.c
index 9dddf2c46..ba1463a01 100644
--- a/dix/events.c
+++ b/dix/events.c
@@ -1839,6 +1839,10 @@ TryClientEvents (ClientPtr client, xEvent *pEvents, int count, Mask mask,
  * Deliver events to a window. At this point, we do not yet know if the event
  * actually needs to be delivered. May activate a grab if the event is a
  * button press.
+ * 
+ * Core events are always delivered to the window owner. If the filter is
+ * something other than CantBeFiltered, the event is also delivered to other
+ * clients with the matching mask on the window.
  *
  * More than one event may be delivered at a time. This is the case with
  * DeviceMotionNotifies which may be followed by DeviceValuator events.
@@ -1964,6 +1968,7 @@ DeliverEventsToWindow(DeviceIntPtr pDev, WindowPtr pWin, xEvent
     if ((type == ButtonPress) && deliveries && (!grab))
     {
 	GrabRec tempGrab;
+        OtherInputMasks *inputMasks;
 
 	tempGrab.device = pDev;
 	tempGrab.resource = client->clientAsMask;
@@ -1975,6 +1980,11 @@ DeliverEventsToWindow(DeviceIntPtr pDev, WindowPtr pWin, xEvent
 	tempGrab.confineTo = NullWindow;
 	tempGrab.cursor = NullCursor;
         tempGrab.coreGrab = True;
+
+        /* get the XI device mask */
+        inputMasks = wOtherInputMasks(pWin);
+        tempGrab.deviceMask = (inputMasks) ? inputMasks->inputEvents[pDev->id]: 0;
+
         tempGrab.genericMasks = NULL;
 	(*inputInfo.pointer->deviceGrab.ActivateGrab)(pDev, &tempGrab,
 					   currentTime, TRUE);
@@ -3221,10 +3231,14 @@ DeliverGrabbedEvent(xEvent *xE, DeviceIntPtr thisDev,
                         grab);
             } else 
             {
+                Mask mask = grab->eventMask;
+                if (grabinfo->fromPassiveGrab && (xE->u.u.type &
+                            EXTENSION_EVENT_BASE))
+                    mask = grab->deviceMask;
+
                 FixUpEventFromWindow(thisDev, xE, grab->window, None, TRUE);
                 deliveries = TryClientEvents(rClient(grab), xE, count,
-                        (Mask)grab->eventMask,
-                        filters[xE->u.u.type], grab);
+                        mask, filters[xE->u.u.type], grab);
             }
             if (deliveries && (xE->u.u.type == MotionNotify
 #ifdef XINPUT
@@ -5716,7 +5730,8 @@ IsInterferingGrab(ClientPtr client, DeviceIntPtr dev, xEvent* event)
     {
         if (it != dev)
         {
-            if (it->deviceGrab.grab && SameClient(it->deviceGrab.grab, client))
+            if (it->deviceGrab.grab && SameClient(it->deviceGrab.grab, client)
+                        && !it->deviceGrab.fromPassiveGrab)
             {
                 return TRUE;
             }
diff --git a/include/inputstr.h b/include/inputstr.h
index a53588461..986232c79 100644
--- a/include/inputstr.h
+++ b/include/inputstr.h
@@ -117,6 +117,9 @@ typedef struct _GenericMaskRec {
  * ButtonPressMask).
  * If the grab is a device grab (GrabDevice), then the eventMask is a
  * combination of event masks for a given XI event type (see SetEventInfo).
+ *
+ * If the grab is a result of a ButtonPress, then eventMask is the core mask
+ * and deviceMask is set to the XI event mask for the grab.
  */
 typedef struct _GrabRec {
     GrabPtr		next;		/* for chain of passive grabs */
@@ -135,6 +138,7 @@ typedef struct _GrabRec {
     WindowPtr		confineTo;	/* always NULL for keyboards */
     CursorPtr		cursor;		/* always NULL for keyboards */
     Mask		eventMask;
+    Mask                deviceMask;     
     GenericMaskPtr      genericMasks;   /* null terminated list */
 } GrabRec;