diff --git a/library/md4.c b/library/md4.c
index 8ac6c01..aa5f539 100644
--- a/library/md4.c
+++ b/library/md4.c
@@ -29,7 +29,11 @@
  *  http://www.ietf.org/rfc/rfc1320.txt
  */
 
+#if !defined(POLARSSL_CONFIG_FILE)
 #include "polarssl/config.h"
+#else
+#include POLARSSL_CONFIG_FILE
+#endif
 
 #if defined(POLARSSL_MD4_C)