diff -r 69ae64637be5 -r a08bbdf839ae tests/run-tests.py
--- a/tests/run-tests.py	Mon Mar 09 05:19:02 2020 +0100
+++ b/tests/run-tests.py	Mon Mar 09 10:18:40 2020 -0700
@@ -1756,7 +1756,7 @@
 
         if self._case:
             casestr = b'#'.join(self._case)
-            if isinstance(self._case, str):
+            if isinstance(casestr, str):
                 quoted = shellquote(casestr)
             else:
                 quoted = shellquote(casestr.decode('utf8')).encode('utf8')