diff --git a/kal/posix/include/bits/alltypes.h b/kal/posix/include/bits/alltypes.h
index 2ba9a82e..e4c5af78 100644
--- a/kal/posix/include/bits/alltypes.h
+++ b/kal/posix/include/bits/alltypes.h
@@ -4,7 +4,7 @@
 #define _Int64 long long
 #define _Reg int
 
-#if __ARMEB__
+#ifdef __ARMEB__
 #define __BYTE_ORDER 4321
 #else
 #define __BYTE_ORDER 1234