diff --git a/games/hack/alloc.c b/games/hack/alloc.c
index d94bf8b903b8..0e46ebce689f 100644
--- a/games/hack/alloc.c
+++ b/games/hack/alloc.c
@@ -1,4 +1,6 @@
 /* alloc.c - version 1.0.2 */
+#include <stdlib.h>
+
 #ifdef LINT
 
 /*
@@ -18,9 +20,6 @@ long dummy = ftell(stderr);
 
 #else
 
-extern char *malloc();
-extern char *realloc();
-
 long *
 alloc(lth)
 register unsigned lth;