--- include/cmocka.h
+++ include/cmocka.h
@@ -56,12 +56,16 @@ int __stdcall IsDebuggerPresent();
 
 /* If __WORDSIZE is not set, try to figure it out and default to 32 bit. */
 #ifndef __WORDSIZE
+#ifndef __GLIBC__
+#include <bits/reg.h>
+#else
 # if defined(__x86_64__) && !defined(__ILP32__)
 #  define __WORDSIZE 64
 # else
 #  define __WORDSIZE 32
 # endif
 #endif
+#endif
 
 #ifdef DOXYGEN
 /**