diff --git a/lib/dns/gen.c b/lib/dns/gen.c
index 99f0395b3a..51d2176a0e 100644
--- a/lib/dns/gen.c
+++ b/lib/dns/gen.c
@@ -26,18 +26,18 @@
 
 #include <sys/types.h>
 
-#include <isc/platform.h>
-
 #include <ctype.h>
+#include <errno.h>
 #include <limits.h>
 #include <stdint.h>
-#include <stdlib.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
-#include <errno.h>
-#include <limits.h>
+
+#ifndef PATH_MAX
+#define PATH_MAX 1024
+#endif
 
 #ifdef WIN32
 #include "gen-win32.h"