diff --git a/src/core/dhcp.c b/src/core/dhcp.c
index f8cb20c0..9b22b5d8 100644
--- a/src/core/dhcp.c
+++ b/src/core/dhcp.c
@@ -79,7 +79,7 @@
 #include "lwip/opt.h"
 #include "lwip/dhcp.h"
 
-#ifdef LWIP_DHCP /* don't build if not configured for use in lwipopt.h */
+#if LWIP_DHCP /* don't build if not configured for use in lwipopt.h */
 
 /** global transaction identifier, must be
  *  unique for each DHCP request. */