diff --git a/tests/test_connection_string.py b/tests/test_connection_string.py
index 81dffebe..0ff84b92 100644
--- a/tests/test_connection_string.py
+++ b/tests/test_connection_string.py
@@ -8,6 +8,8 @@
     [
         "unix://tmp/foo.bar?db=1",
         "redis://localhost/2",
+        "redis://redis-master/0?is_master=0",
+        "redis://redis-master/2?is_master=False",
         "rediss://localhost:3333?db=2",
     ],
 )