--- a/chrome/src/nsChromeRegistry.cpp
+++ b/chrome/src/nsChromeRegistry.cpp
@@ -1652,17 +1652,17 @@ nsChromeRegistry::ProcessManifestBuffer(
 #if defined(XP_WIN)
   OSVERSIONINFO info = { sizeof(OSVERSIONINFO) };
   if (GetVersionEx(&info)) {
     nsTextFormatter::ssprintf(osVersion, NS_LITERAL_STRING("%ld.%ld").get(),
                                          info.dwMajorVersion,
                                          info.dwMinorVersion);
   }
 #elif defined(XP_MACOSX)
-  long majorVersion, minorVersion;
+  SInt32 majorVersion, minorVersion;
   if ((Gestalt(gestaltSystemVersionMajor, &majorVersion) == noErr) &&
       (Gestalt(gestaltSystemVersionMinor, &minorVersion) == noErr)) {
     nsTextFormatter::ssprintf(osVersion, NS_LITERAL_STRING("%ld.%ld").get(),
                                          majorVersion,
                                          minorVersion);
   }
 #elif defined(MOZ_WIDGET_GTK2)
   nsTextFormatter::ssprintf(osVersion, NS_LITERAL_STRING("%ld.%ld").get(),

--- a/toolkit/xre/nsNativeAppSupportCocoa.mm
+++ b/toolkit/xre/nsNativeAppSupportCocoa.mm
@@ -101,17 +101,17 @@ nsNativeAppSupportCocoa::Enable()
   mCanShowUI = PR_TRUE;
   return NS_OK;
 }
 
 NS_IMETHODIMP nsNativeAppSupportCocoa::Start(PRBool *_retval)
 {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT;
 
-  long response = 0;
+  SInt32 response = 0;
   OSErr err = ::Gestalt (gestaltSystemVersion, &response);
   response &= 0xFFFF; // The system version is in the low order word
 
   // Check for at least Mac OS X 10.4, and if that fails return PR_FALSE,
   // which will make the browser quit.  In principle we could display an
   // alert here.  But the alert's message and buttons would require custom
   // localization.  So (for now at least) we just log an English message
   // to the console before quitting.