diff --git a/js/src/xpconnect/src/XPCIDispatchExtension.cpp b/js/src/xpconnect/src/XPCIDispatchExtension.cpp
index 5f2c5b37209..4a3920be590 100644
--- a/js/src/xpconnect/src/XPCIDispatchExtension.cpp
+++ b/js/src/xpconnect/src/XPCIDispatchExtension.cpp
@@ -54,7 +54,7 @@ CommonConstructor(JSContext *cx, int name, JSObject *obj, uintN argc,
     nsIXPCSecurityManager* sm = ccx.GetXPCContext()
         ->GetAppropriateSecurityManager(nsIXPCSecurityManager::HOOK_CALL_METHOD);
     XPCWrappedNative * wrapper = ccx.GetWrapper();
-    if(!sm || NS_FAILED(sm->CanAccess(nsIXPCSecurityManager::ACCESS_CALL_METHOD,
+    if(sm && NS_FAILED(sm->CanAccess(nsIXPCSecurityManager::ACCESS_CALL_METHOD,
                                       &ccx, ccx, ccx.GetFlattenedJSObject(),
                                       wrapper->GetIdentityObject(),
                                       wrapper->GetClassInfo(),
diff --git a/js/src/xpconnect/src/nsDispatchSupport.cpp b/js/src/xpconnect/src/nsDispatchSupport.cpp
index 31fd51f6a5e..970cda3458f 100644
--- a/js/src/xpconnect/src/nsDispatchSupport.cpp
+++ b/js/src/xpconnect/src/nsDispatchSupport.cpp
@@ -203,7 +203,7 @@ NS_IMETHODIMP nsDispatchSupport::IsClassSafeToHost(JSContext * cx,
     nsIXPCSecurityManager* sm =
             ccx.GetXPCContext()->GetAppropriateSecurityManager(
                         nsIXPCSecurityManager::HOOK_CREATE_INSTANCE);
-    *aResult = sm && 
+    *aResult = !sm ||
         NS_SUCCEEDED(sm->CanCreateInstance(ccx, cid));
 
     if(!*aResult)