diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl
index d752c4bd0d8b..28eebfa32621 100755
--- a/tools/testing/ktest/ktest.pl
+++ b/tools/testing/ktest/ktest.pl
@@ -4106,7 +4106,8 @@ sub __set_test_option {
 
     my $option = "$name\[$i\]";
 
-    if (option_defined($option)) {
+    if (exists($opt{$option})) {
+	return undef if (!option_defined($option));
 	return $opt{$option};
     }
 
@@ -4114,7 +4115,8 @@ sub __set_test_option {
 	if ($i >= $test &&
 	    $i < $test + $repeat_tests{$test}) {
 	    $option = "$name\[$test\]";
-	    if (option_defined($option)) {
+	    if (exists($opt{$option})) {
+		return undef if (!option_defined($option));
 		return $opt{$option};
 	    }
 	}