diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index c80fd17c..15167289 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -1788,11 +1788,11 @@
  * using our cleaned PolarSSL library.
  */
 
-#if CHAP_SUPPORT || EAP_SUPPORT
+#if CHAP_SUPPORT || EAP_SUPPORT || MD5_SUPPORT
 #ifndef LWIP_INCLUDED_POLARSSL_MD5
 #define LWIP_INCLUDED_POLARSSL_MD5	1	/* CHAP and EAP require MD5 support */
 #endif /* LWIP_INCLUDED_POLARSSL_MD5 */
-#endif /* CHAP_SUPPORT || EAP_SUPPORT */
+#endif /* CHAP_SUPPORT || EAP_SUPPORT || MD5_SUPPORT */
 
 #if MSCHAP_SUPPORT
 #ifndef LWIP_INCLUDED_POLARSSL_MD4