1 files changed, 3 insertions, 1 deletions
diff --git a/util-src/crand.c b/util-src/crand.c
index cdc3c211..20871f3e 100644
--- a/util-src/crand.c
+++ b/util-src/crand.c
@@ -69,7 +69,9 @@ int getrandom(void *buf, size_t buflen, unsigned int flags) {
 int Lrandom(lua_State *L) {
 	char smallbuf[SMALLBUFSIZ];
 	char *buf = &smallbuf[0];
-	const size_t len = luaL_checkinteger(L, 1);
+	const lua_Integer l = luaL_checkinteger(L, 1);
+	const size_t len = l;
+	luaL_argcheck(L, l >= 0, 1, "must be > 0");
 
 	if(len > SMALLBUFSIZ) {
 		buf = lua_newuserdata(L, len);