diff --git a/caps/src/nsScriptSecurityManager.cpp b/caps/src/nsScriptSecurityManager.cpp
index df36a8d470e..fad1c515f53 100644
--- a/caps/src/nsScriptSecurityManager.cpp
+++ b/caps/src/nsScriptSecurityManager.cpp
@@ -918,7 +918,7 @@ nsScriptSecurityManager::CheckSameOriginPrincipalInternal(nsIPrincipal* aSubject
         nsXPIDLCString origin;
         rv = aObject->GetOrigin(getter_Copies(origin));
         NS_ENSURE_SUCCESS(rv, rv);
-        if (nsCRT::strcasecmp(origin, "about:blank") == 0)
+        if (nsCRT::strcasecmp(origin, "moz-safe-about:blank") == 0)
             return NS_OK;
     }
 
diff --git a/netwerk/build/nsNetModule.cpp b/netwerk/build/nsNetModule.cpp
index e2511bcd419..122a80db43c 100644
--- a/netwerk/build/nsNetModule.cpp
+++ b/netwerk/build/nsNetModule.cpp
@@ -989,7 +989,7 @@ static const nsModuleComponentInfo gNetModuleInfo[] = {
     },
     { NS_SAFEABOUTPROTOCOLHANDLER_CLASSNAME,
       NS_SAFEABOUTPROTOCOLHANDLER_CID,
-      NS_NETWORK_PROTOCOL_CONTRACTID_PREFIX "safe-about", 
+      NS_NETWORK_PROTOCOL_CONTRACTID_PREFIX "moz-safe-about", 
       nsSafeAboutProtocolHandlerConstructor
     },
     { "about:blank", 
diff --git a/netwerk/protocol/about/src/nsAboutProtocolHandler.cpp b/netwerk/protocol/about/src/nsAboutProtocolHandler.cpp
index df01280ca1a..52dbbc454e3 100644
--- a/netwerk/protocol/about/src/nsAboutProtocolHandler.cpp
+++ b/netwerk/protocol/about/src/nsAboutProtocolHandler.cpp
@@ -117,10 +117,18 @@ nsAboutProtocolHandler::NewURI(const nsACString &aSpec,
     }
 
     if (isSafe) {
-        // We need to indicate that this baby is safe.  Use an inner
-        // URI that no one but the security manager will see.
+        // We need to indicate that this baby is safe.  Use an inner URI that
+        // no one but the security manager will see.  Make sure to preserve our
+        // path, in case someone decides to hardcode checks for particular
+        // about: URIs somewhere.
+        nsCAutoString spec;
+        rv = url->GetPath(spec);
+        NS_ENSURE_SUCCESS(rv, rv);
+        
+        spec.Insert("moz-safe-about:", 0);
+
         nsCOMPtr<nsIURI> inner;
-        rv = NS_NewURI(getter_AddRefs(inner), "moz-safe-about:x");
+        rv = NS_NewURI(getter_AddRefs(inner), spec);
         NS_ENSURE_SUCCESS(rv, rv);
 
         nsSimpleNestedURI* outer = new nsSimpleNestedURI(inner);