diff --git a/library/arc4.c b/library/arc4.c
index b8998ac..2109bb2 100644
--- a/library/arc4.c
+++ b/library/arc4.c
@@ -24,11 +24,7 @@
  *  http://groups.google.com/group/sci.crypt/msg/10a300c9d21afca0
  */
 
-#if !defined(MBEDTLS_CONFIG_FILE)
-#include "mbedtls/config.h"
-#else
-#include MBEDTLS_CONFIG_FILE
-#endif
+#include "common.h"
 
 #if defined(MBEDTLS_ARC4_C)