diff --git a/Source/NSLock.m b/Source/NSLock.m
index e55a8d0786..30fc4246bd 100644
--- a/Source/NSLock.m
+++ b/Source/NSLock.m
@@ -36,13 +36,14 @@
 #import "GSPrivate.h"
 #import "GSPThread.h"
 #include <math.h>
+#include <stdlib.h>
 
 #import "common.h"
 
 #import "Foundation/NSLock.h"
 #import "Foundation/NSException.h"
 #import "Foundation/NSThread.h"
-#import "Foundation/NSUserDefaults.h"
+// #import "Foundation/NSUserDefaults.h"
 
 #define class_createInstance(C,E) NSAllocateObject(C,E,NSDefaultMallocZone())
 
@@ -348,7 +349,7 @@ + (void) initialize
       untracedConditionLockClass = [GSUntracedConditionLock class];
       untracedLockClass = [GSUntracedLock class];
       untracedRecursiveLockClass = [GSUntracedRecursiveLock class];
-      compatible = [[NSUserDefaults standardUserDefaults] boolForKey: @"GSMacOSXCompatible"];
+      compatible = (strcmp(getenv("NSLOCK_COMPATIBLE"), "YES") == 0) ? YES : NO;
     }
 }