diff --git a/cachecontrol/serialize.py b/cachecontrol/serialize.py
index f0c215c..738fac7 100644
--- a/cachecontrol/serialize.py
+++ b/cachecontrol/serialize.py
@@ -137,6 +137,9 @@ def prepare_response(self, request, cached, body_file=None):
             #     TypeError: 'str' does not support the buffer interface
             body = io.BytesIO(body_raw.encode("utf8"))
 
+        # Discard any `strict` parameter serialized by older version of cachecontrol.
+        cached["response"].pop("strict", None)
+
         return HTTPResponse(body=body, preload_content=False, **cached["response"])
 
     def _loads_v0(self, request, data, body_file=None):