diff --git a/tests/test_functions.bash b/tests/test_functions.bash
index 6397d088b..37344ed80 100644
--- a/tests/test_functions.bash
+++ b/tests/test_functions.bash
@@ -64,7 +64,7 @@ function run_disk_element_test() {
             echo "No image $dest_dir/image.tar found!"
             exit 1
         else
-            if tar -t $dest_dir/image.tar | grep -q /tmp/dib-test-should-fail; then
+            if tar -tf $dest_dir/image.tar | grep -q /tmp/dib-test-should-fail; then
                 echo "Error: Element: $element, test-element $test_element should have failed, but passed."
                 exit 1
             else