diff --git a/src/tool_writeout.c b/src/tool_writeout.c
index 6879a98c264d7b..2e4481d02bf76d 100644
--- a/src/tool_writeout.c
+++ b/src/tool_writeout.c
@@ -246,7 +246,7 @@ static int writeLong(FILE *stream, const struct writeoutvar *wovar,
       valid = true;
       break;
     case VAR_URLNUM:
-      if(per->urlnum <= LONG_MAX) {
+      if((unsigned long)per->urlnum <= LONG_MAX) {
         longinfo = (long)per->urlnum;
         valid = true;
       }