diff --git a/js/src/xpconnect/src/XPCCrossOriginWrapper.cpp b/js/src/xpconnect/src/XPCCrossOriginWrapper.cpp
index 74c60482fe38..dfaf8e7f1220 100644
--- a/js/src/xpconnect/src/XPCCrossOriginWrapper.cpp
+++ b/js/src/xpconnect/src/XPCCrossOriginWrapper.cpp
@@ -177,19 +177,11 @@ GetWrappedObject(JSContext *cx, JSObject *wrapper)
 
 static inline
 nsIScriptSecurityManager *
-GetSecurityManager(JSContext *cx)
+GetSecurityManager()
 {
-  XPCCallContext ccx(JS_CALLER, cx);
-  NS_ENSURE_TRUE(ccx.IsValid(), nsnull);
+  extern nsIScriptSecurityManager *gScriptSecurityManager;
 
-  // XXX HOOK_CALL_METHOD seems wrong.
-  nsCOMPtr<nsIXPCSecurityManager> sm = ccx.GetXPCContext()->
-    GetAppropriateSecurityManager(nsIXPCSecurityManager::HOOK_CALL_METHOD);
-
-  nsCOMPtr<nsIScriptSecurityManager> ssm(do_QueryInterface(sm));
-
-  // This Releases, but that's OK, since XPConnect holds a reference to it.
-  return ssm;
+  return gScriptSecurityManager;
 }
 
 static JSBool
@@ -234,7 +226,7 @@ IsWrapperSameOrigin(JSContext *cx, JSObject *wrappedObj)
   nsCOMPtr<nsIPrincipal> subjectPrin, objectPrin;
 
   // Get the subject principal from the execution stack.
-  nsIScriptSecurityManager *ssm = GetSecurityManager(cx);
+  nsIScriptSecurityManager *ssm = GetSecurityManager();
   if (!ssm) {
     ThrowException(NS_ERROR_NOT_INITIALIZED, cx);
     return NS_ERROR_NOT_INITIALIZED;
@@ -626,7 +618,7 @@ XPC_XOW_GetOrSetProperty(JSContext *cx, JSObject *obj, jsval id, jsval *vp,
       XPCWrappedNative::GetWrappedNativeOfJSObject(cx, wrappedObj);
     NS_ASSERTION(wn, "How did we wrap a non-WrappedNative?");
     if (!IsValFrame(cx, wrappedObj, id, wn)) {
-      nsIScriptSecurityManager *ssm = GetSecurityManager(cx);
+      nsIScriptSecurityManager *ssm = GetSecurityManager();
       if (!ssm) {
         return ThrowException(NS_ERROR_NOT_INITIALIZED, cx);
       }
@@ -772,7 +764,7 @@ XPC_XOW_NewResolve(JSContext *cx, JSObject *obj, jsval id, uintN flags,
       XPCWrappedNative::GetWrappedNativeOfJSObject(cx, wrappedObj);
     NS_ASSERTION(wn, "How did we wrap a non-WrappedNative?");
     if (!IsValFrame(cx, wrappedObj, id, wn)) {
-      nsIScriptSecurityManager *ssm = GetSecurityManager(cx);
+      nsIScriptSecurityManager *ssm = GetSecurityManager();
       if (!ssm) {
         return ThrowException(NS_ERROR_NOT_INITIALIZED, cx);
       }
@@ -1146,7 +1138,7 @@ XPC_XOW_toString(JSContext *cx, JSObject *obj, uintN argc, jsval *argv,
 
   nsresult rv = IsWrapperSameOrigin(cx, wrappedObj);
   if (rv == NS_ERROR_DOM_PROP_ACCESS_DENIED) {
-    nsIScriptSecurityManager *ssm = GetSecurityManager(cx);
+    nsIScriptSecurityManager *ssm = GetSecurityManager();
     if (!ssm) {
       return ThrowException(NS_ERROR_NOT_INITIALIZED, cx);
     }
diff --git a/js/src/xpconnect/src/nsXPConnect.cpp b/js/src/xpconnect/src/nsXPConnect.cpp
index 97a39839097a..7e6a554eb37d 100644
--- a/js/src/xpconnect/src/nsXPConnect.cpp
+++ b/js/src/xpconnect/src/nsXPConnect.cpp
@@ -60,6 +60,10 @@ NS_IMPL_THREADSAFE_ISUPPORTS3(nsXPConnect,
 nsXPConnect* nsXPConnect::gSelf = nsnull;
 JSBool       nsXPConnect::gOnceAliveNowDead = JS_FALSE;
 
+// Global cache of the default script security manager (QI'd to
+// nsIScriptSecurityManager)
+nsIScriptSecurityManager *gScriptSecurityManager = nsnull;
+
 const char XPC_CONTEXT_STACK_CONTRACTID[] = "@mozilla.org/js/xpc/ContextStack;1";
 const char XPC_RUNTIME_CONTRACTID[]       = "@mozilla.org/js/xpc/RuntimeService;1";
 const char XPC_EXCEPTION_CONTRACTID[]     = "@mozilla.org/js/xpc/Exception;1";
@@ -151,6 +155,8 @@ nsXPConnect::~nsXPConnect()
     NS_IF_RELEASE(mContextStack);
     NS_IF_RELEASE(mDefaultSecurityManager);
 
+    gScriptSecurityManager = nsnull;
+
     // shutdown the logging system
     XPC_LOG_FINISH();
 
@@ -1511,6 +1517,14 @@ nsXPConnect::SetDefaultSecurityManager(nsIXPCSecurityManager *aManager,
     NS_IF_RELEASE(mDefaultSecurityManager);
     mDefaultSecurityManager = aManager;
     mDefaultSecurityManagerFlags = flags;
+
+    nsCOMPtr<nsIScriptSecurityManager> ssm =
+        do_QueryInterface(mDefaultSecurityManager);
+
+    // Remember the result of the above QI for fast access to the
+    // script securityt manager.
+    gScriptSecurityManager = ssm;
+
     return NS_OK;
 }