diff --git a/dom/plugins/ipc/PPluginModule.ipdl b/dom/plugins/ipc/PPluginModule.ipdl
index fbb6e722f4f..325a7273bf9 100644
--- a/dom/plugins/ipc/PPluginModule.ipdl
+++ b/dom/plugins/ipc/PPluginModule.ipdl
@@ -39,6 +39,7 @@
 
 include protocol PPluginIdentifier;
 include protocol PPluginInstance;
+include protocol PPluginScriptableObject;
 
 include "npapi.h";
 include "mozilla/plugins/PluginMessageUtils.h";
@@ -153,6 +154,9 @@ parent:
   async PushCursor(NSCursorInfo cursorInfo);
   async PopCursor();
   sync GetNativeCursorsSupported() returns (bool supported);
+
+  sync NPN_SetException(nullable PPluginScriptableObject actor,
+                        nsCString message);
 };
 
 } // namespace plugins
diff --git a/dom/plugins/ipc/PluginModuleChild.cpp b/dom/plugins/ipc/PluginModuleChild.cpp
index f437b352dad..94240ffe58f 100644
--- a/dom/plugins/ipc/PluginModuleChild.cpp
+++ b/dom/plugins/ipc/PluginModuleChild.cpp
@@ -1516,7 +1516,19 @@ _setexception(NPObject* aNPObj,
 {
     PLUGIN_LOG_DEBUG_FUNCTION;
     ENSURE_PLUGIN_THREAD_VOID();
-    NS_WARNING("Not yet implemented!");
+
+    PluginModuleChild* self = PluginModuleChild::current();
+    PluginScriptableObjectChild* actor = NULL;
+    if (aNPObj) {
+        actor = self->GetActorForNPObject(aNPObj);
+        if (!actor) {
+            NS_ERROR("Failed to get actor!");
+            return;
+        }
+    }
+
+    self->SendNPN_SetException(static_cast<PPluginScriptableObjectChild*>(actor),
+                               NullableString(aMessage));
 }
 
 void NP_CALLBACK
diff --git a/dom/plugins/ipc/PluginModuleParent.cpp b/dom/plugins/ipc/PluginModuleParent.cpp
index c48e926c2c1..aceb7492eee 100644
--- a/dom/plugins/ipc/PluginModuleParent.cpp
+++ b/dom/plugins/ipc/PluginModuleParent.cpp
@@ -1209,3 +1209,21 @@ PluginModuleParent::RemoveFromRefreshTimer(PluginInstanceParent *aInstance) {
     }
 }
 #endif
+
+bool
+PluginModuleParent::RecvNPN_SetException(PPluginScriptableObjectParent* aActor,
+                                         const nsCString& aMessage)
+{
+    PLUGIN_LOG_DEBUG(("%s", FULLFUNCTION));
+
+    NPObject* aNPObj = NULL;
+    if (aActor) {
+        aNPObj = static_cast<PluginScriptableObjectParent*>(aActor)->GetObject(true);
+        if (!aNPObj) {
+            NS_ERROR("Failed to get object!");
+            return false;
+        }
+    }
+    mozilla::plugins::parent::_setexception(aNPObj, NullableStringGet(aMessage));
+    return true;
+}
diff --git a/dom/plugins/ipc/PluginModuleParent.h b/dom/plugins/ipc/PluginModuleParent.h
index 4efb3500363..576dddb7f31 100644
--- a/dom/plugins/ipc/PluginModuleParent.h
+++ b/dom/plugins/ipc/PluginModuleParent.h
@@ -210,6 +210,10 @@ protected:
     NS_OVERRIDE virtual bool
     RecvGetNativeCursorsSupported(bool* supported);
 
+    NS_OVERRIDE virtual bool
+    RecvNPN_SetException(PPluginScriptableObjectParent* aActor,
+                         const nsCString& aMessage);
+
     static PluginInstanceParent* InstCast(NPP instance);
     static BrowserStreamParent* StreamCast(NPP instance, NPStream* s);
 
diff --git a/dom/plugins/test/mochitest/Makefile.in b/dom/plugins/test/mochitest/Makefile.in
index dc48592f145..0e27707eee0 100644
--- a/dom/plugins/test/mochitest/Makefile.in
+++ b/dom/plugins/test/mochitest/Makefile.in
@@ -102,10 +102,10 @@ _MOCHITEST_FILES = \
   test_clear_site_data.html \
   test_zero_opacity.html \
   test_NPPVpluginWantsAllNetworkStreams.html \
+  test_npruntime_npnsetexception.html \
   $(NULL)
 
 #  test_plugin_scroll_painting.html \ bug 596491
-#  test_npruntime_npnsetexception.html \ Disabled for e10s
 
 ifeq ($(OS_ARCH),WINNT)
 _MOCHITEST_FILES += \