diff --git a/widget/src/mac/nsMacResources.cpp b/widget/src/mac/nsMacResources.cpp
index cd00d0a07c38..064068d54bc3 100644
--- a/widget/src/mac/nsMacResources.cpp
+++ b/widget/src/mac/nsMacResources.cpp
@@ -36,8 +36,7 @@
  * ***** END LICENSE BLOCK ***** */
 
 #include "nsMacResources.h"
-#include <Resources.h>
-#include <Processes.h>
+#include <Carbon/Carbon.h>
 
 short nsMacResources::mRefNum      = kResFileNotOpened;
 short nsMacResources::mSaveResFile = 0;
@@ -46,21 +45,26 @@ short nsMacResources::mSaveResFile = 0;
 nsresult nsMacResources::OpenLocalResourceFile()
 {
   if (mRefNum == kResFileNotOpened) {
-    ProcessSerialNumber PSN;
-    ProcessInfoRec pinfo;
-    FSSpec appSpec;
-
-    PSN.highLongOfPSN = 0;
-    PSN.lowLongOfPSN = kCurrentProcess;
-    pinfo.processInfoLength = sizeof(pinfo);
-    pinfo.processName = NULL;
-    pinfo.processAppSpec = &appSpec;
-
-    if (GetProcessInformation(&PSN, &pinfo) == noErr) {
-      FSSpec resSpec = { appSpec.vRefNum, appSpec.parID, "\plibwidget.rsrc" };
-      FSRef resRef;
-      if (FSpMakeFSRef(&resSpec, &resRef) == noErr)
-        FSOpenResourceFile(&resRef, 0, NULL, fsRdPerm, &mRefNum);
+    CFBundleRef appBundle = ::CFBundleGetMainBundle();
+    if (appBundle) {
+      CFURLRef executable = ::CFBundleCopyExecutableURL(appBundle);
+      if (executable) {
+        CFURLRef binDir = ::CFURLCreateCopyDeletingLastPathComponent(
+                           kCFAllocatorDefault, executable);
+        if (binDir) {
+          CFURLRef resourceFile = ::CFURLCreateCopyAppendingPathComponent(
+                                   kCFAllocatorDefault, binDir,
+                                   CFSTR("libwidget.rsrc"), PR_FALSE);
+          if (resourceFile) {
+            FSRef resourceRef;
+            if (::CFURLGetFSRef(resourceFile, &resourceRef))
+              ::FSOpenResourceFile(&resourceRef, 0, NULL, fsRdPerm, &mRefNum);
+            ::CFRelease(resourceFile);
+          }
+          ::CFRelease(binDir);
+        }
+        ::CFRelease(executable);
+      }
     }
   }
   if (mRefNum == kResFileNotOpened)