diff --git a/redis/connection.py b/redis/connection.py
index 1f862d0371..61ef1e8ffa 100644
--- a/redis/connection.py
+++ b/redis/connection.py
@@ -956,6 +956,7 @@ def to_bool(value):
     "health_check_interval": int,
     "ssl_check_hostname": to_bool,
     "timeout": float,
+    "is_master": to_bool,
 }
 
 
diff --git a/tests/test_connection_pool.py b/tests/test_connection_pool.py
index dee7c554d3..c2a590c5c4 100644
--- a/tests/test_connection_pool.py
+++ b/tests/test_connection_pool.py
@@ -321,6 +321,11 @@ def test_extra_querystring_options(self):
         assert pool.connection_class == redis.Connection
         assert pool.connection_kwargs == {"host": "localhost", "a": "1", "b": "2"}
 
+    def test_ismaster_querystring(self):
+        pool = redis.ConnectionPool.from_url("redis://localhost?1&ismaster=0")
+        assert pool.connection_class == redis.Connection
+        assert pool.connection_kwargs == {"host": "localhost", "db": 1,"ismaster": False}
+
     def test_calling_from_subclass_returns_correct_instance(self):
         pool = redis.BlockingConnectionPool.from_url("redis://localhost")
         assert isinstance(pool, redis.BlockingConnectionPool)