diff --git a/lib/imagelib.c b/lib/imagelib.c
index f71b96a..49c7545 100644
--- a/lib/imagelib.c
+++ b/lib/imagelib.c
@@ -2,6 +2,7 @@
 #include <string.h>
 #include "imagelib.h"
 #include "cards.h"
+#include <stdlib.h>

 image_list *image_root = 0;

diff --git a/lib/make-imglib.c b/lib/make-imglib.c
index 84cda12..8edaa0f 100644
--- a/lib/make-imglib.c
+++ b/lib/make-imglib.c
@@ -7,6 +7,7 @@
 #include <dirent.h>

 #include <png.h>
+#include <ctype.h>

 static int verbose = 0;
 static char *basename = "images";
@@ -202,7 +203,7 @@ tokenize(char *string)
   char *rv;
   if (string) {
     next = string;
-    return;
+    return NULL; // this value is unused, so it can be anything
   }
   while (*next && !isgraph(*next)) next++;
   if (!*next) return 0;