diff --git a/tests/test-revert-unknown.out b/tests/test-revert-unknown.out
new file mode 100644
--- /dev/null
+++ b/tests/test-revert-unknown.out
@@ -0,0 +1,8 @@
+%% Should show unknown
+? unknown
+%% Should show unknown and b removed
+R b
+? unknown
+%% Should show a and unknown
+a
+unknown