diff --git a/tests/runtests.pl b/tests/runtests.pl
index a326fc37b6..d938e18694 100755
--- a/tests/runtests.pl
+++ b/tests/runtests.pl
@@ -2541,7 +2541,7 @@ while(@ARGV) {
     }
     elsif($ARGV[0] eq "-k") {  # delete this check after December 2026
         print "Option -k became always-on in 7.65.2 (2019) and now a no-op. Delete it to continue.\n";
-        exit;
+        exit 1;
     }
     elsif($ARGV[0] eq "-r") {
         # run time statistics needs Time::HiRes