--- a/widget/cocoa/nsToolkit.mm
+++ b/widget/cocoa/nsToolkit.mm
@@ -285,20 +285,17 @@ nsToolkit* nsToolkit::GetToolkit()
 }
 
 // An alternative to [NSObject poseAsClass:] that isn't deprecated on OS X
 // Leopard and is available to 64-bit binaries on Leopard and above.  Based on
 // ideas and code from http://www.cocoadev.com/index.pl?MethodSwizzling.
 // Since the Method type becomes an opaque type as of Objective-C 2.0, we'll
 // have to switch to using accessor methods like method_exchangeImplementations()
 // when we build 64-bit binaries that use Objective-C 2.0 (on and for Leopard
-// and above).  But these accessor methods aren't available in Objective-C 1
-// (or on Tiger).  So we need to access Method's members directly for (Tiger-
-// capable) binaries (32-bit or 64-bit) that use Objective-C 1 (as long as we
-// keep supporting Tiger).
+// and above).
 //
 // Be aware that, if aClass doesn't have an orgMethod selector but one of its
 // superclasses does, the method substitution will (in effect) take place in
 // that superclass (rather than in aClass itself).  The substitution has
 // effect on the class where it takes place and all of that class's
 // subclasses.  In order for method swizzling to work properly, posedMethod
 // needs to be unique in the class where the substitution takes place and all
 // of its subclasses.
@@ -316,20 +313,14 @@ nsresult nsToolkit::SwizzleMethods(Class
   } else {
     original = class_getInstanceMethod(aClass, orgMethod);
     posed = class_getInstanceMethod(aClass, posedMethod);
   }
 
   if (!original || !posed)
     return NS_ERROR_FAILURE;
 
-#ifdef __LP64__
   method_exchangeImplementations(original, posed);
-#else
-  IMP aMethodImp = original->method_imp;
-  original->method_imp = posed->method_imp;
-  posed->method_imp = aMethodImp;
-#endif
 
   return NS_OK;
 
   NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;
 }