--- a/tests/test-nested-repo
+++ b/tests/test-nested-repo
@@ -13,6 +13,10 @@ echo '# should fail'
 hg st b/x
 hg add b/x
 
+echo '# should fail'
+hg add b b/x
+hg st
+
 echo '# should arguably print nothing'
 hg st b