diff --git a/requests/adapters.py b/requests/adapters.py
index d3b2d5bb1e..d7967b6d4c 100644
--- a/requests/adapters.py
+++ b/requests/adapters.py
@@ -142,6 +142,8 @@ def __init__(
     ):
         if max_retries == DEFAULT_RETRIES:
             self.max_retries = Retry(0, read=False)
+        elif isinstance(max_retries, Retry):
+            self.max_retries = max_retries
         else:
             self.max_retries = Retry.from_int(max_retries)
         self.config = {}