diff --git a/tests/runtests.pl b/tests/runtests.pl
index 7d469c618c3ad95615181ea6fb29ad4edbf907a6..40226c681169676c4d110c762439175d45565ea2 100755
--- a/tests/runtests.pl
+++ b/tests/runtests.pl
@@ -2635,7 +2635,7 @@ sub checksystem {
     my $versnoexec;
     my @version=();
     my @disabled;
-    my $dis;
+    my $dis = "";
 
     my $curlverout="$LOGDIR/curlverout.log";
     my $curlvererr="$LOGDIR/curlvererr.log";