diff --git a/java/xpcom/xpcom/bcXPCOMProxy.cpp b/java/xpcom/xpcom/bcXPCOMProxy.cpp
index 8f5fb38ba887..ff8391cd4b02 100644
--- a/java/xpcom/xpcom/bcXPCOMProxy.cpp
+++ b/java/xpcom/xpcom/bcXPCOMProxy.cpp
@@ -153,9 +153,13 @@ NS_IMETHODIMP bcXPCOMProxy::CallMethod(PRUint16 methodIndex,
     }  
     NS_IF_RELEASE(eventQ);
     bcIUnMarshaler * unmarshaler = call->GetUnMarshaler();
-    mt->UnMarshal(unmarshaler);
+    nsresult result;
+    unmarshaler->ReadSimple(&result, bc_T_U32);
+    if (NS_SUCCEEDED(result)) {
+        mt->UnMarshal(unmarshaler);
+    }
     delete call; delete marshaler; delete unmarshaler; delete mt;
-    return NS_OK;
+    return result;
 }
 
 nsrefcnt bcXPCOMProxy::AddRef(void) { 
diff --git a/java/xpcom/xpcom/bcXPCOMStub.cpp b/java/xpcom/xpcom/bcXPCOMStub.cpp
index a483b02607d2..4a2e5e5cf7e5 100644
--- a/java/xpcom/xpcom/bcXPCOMStub.cpp
+++ b/java/xpcom/xpcom/bcXPCOMStub.cpp
@@ -111,10 +111,12 @@ void bcXPCOMStub::DispatchAndSaveThread(bcICall *call, nsIEventQueue *eventQueue
     stubsAndProxiesService->PushEventQueue(eventQueue);
     //nb return value; excepion handling
     PR_LOG(log, PR_LOG_DEBUG, ("--bcXPCOMStub::DispatchAndSaveThreade about to XPTC_InvokeByIndex\n"));
-    XPTC_InvokeByIndex(object, mid, paramCount, params);
+    nsresult result = XPTC_InvokeByIndex(object, mid, paramCount, params);
     PR_LOG(log, PR_LOG_DEBUG, ("--bcXPCOMStub::DispatchAndSaveThreade after XPTC_InvokeByIndex\n"));
-    if (mt != NULL) { //nb to do what about nsresult ?
-        bcIMarshaler * m = call->GetMarshaler();
+    bcIMarshaler * m = call->GetMarshaler();
+    m->WriteSimple(&result, bc_T_U32); 
+    if (NS_SUCCEEDED(result)
+        && mt != NULL) { 
         PR_LOG(log, PR_LOG_DEBUG, ("--bcXPCOMStub::DispatchAndSaveThreade about to mt->Marshal\n"));
         mt->Marshal(m);
         delete m;