diff --git a/include/haproxy/defaults.h b/include/haproxy/defaults.h
index e07ff32..1605881 100644
--- a/include/haproxy/defaults.h
+++ b/include/haproxy/defaults.h
@@ -284,7 +284,7 @@
 
 /* Maximum host name length */
 #ifndef MAX_HOSTNAME_LEN
-#if MAXHOSTNAMELEN
+#ifdef MAXHOSTNAMELEN
 #define MAX_HOSTNAME_LEN	MAXHOSTNAMELEN
 #else
 #define MAX_HOSTNAME_LEN	64