diff --git a/src/system/libroot/posix/glibc/include/bits/libc-lock.h b/src/system/libroot/posix/glibc/include/bits/libc-lock.h
index 3852e6ffd7..5a1b5d1811 100644
--- a/src/system/libroot/posix/glibc/include/bits/libc-lock.h
+++ b/src/system/libroot/posix/glibc/include/bits/libc-lock.h
@@ -5,8 +5,9 @@
 #ifndef _BITS_LIBC_LOCK_H
 #define _BITS_LIBC_LOCK_H 1
 
-#include <OS.h>
 #include <Errors.h>
+#include <OS.h>
+#include <SupportDefs.h>
 
 
 /* Helper definitions and prototypes.  */
@@ -15,24 +16,13 @@
 
 extern char	_single_threaded;
 
-#ifdef __INTEL__
-
-// ToDo: this does not belong here!
-
 static inline int
 __compare_and_swap (volatile int32 *p, int oldval, int newval)
 {
-  char ret;
-  long int readval;
-
-  __asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0"
-			: "=q" (ret), "=m" (*p), "=a" (readval)
-			: "r" (newval), "m" (*p), "a" (oldval));
-  return ret;
+	int32 readval = atomic_test_and_set(p, newval, oldval);
+	return (readval == oldval ? 1 : 0);
 }
 
-#endif
-
 
 /* Mutex type.  */
 typedef struct __libc_lock_t {