diff --git a/lib/errno.h b/lib/errno.h
index 2fc4f77a..e84a2bc7 100644
--- a/lib/errno.h
+++ b/lib/errno.h
@@ -14,7 +14,7 @@
 
 #if defined(__ICCARM__)
 # include <metal/compiler/iar/errno.h>
-#elif defined(__CC_ARM) || defined(__arm__)
+#elif defined(__CC_ARM)
 # include <metal/compiler/armcc/errno.h>
 #else
 # include <errno.h>