diff --git a/changelogs/fragments/10136-cache-pickle-json.yml b/changelogs/fragments/10136-cache-pickle-json.yml
new file mode 100644
index 0000000000..a527e5c4b7
--- /dev/null
+++ b/changelogs/fragments/10136-cache-pickle-json.yml
@@ -0,0 +1,2 @@
+bugfixes:
+  - pickle cache plugin - avoid extra JSON serialization with ansible-core >= 2.19 (https://github.com/ansible-collections/community.general/pull/10136).
diff --git a/plugins/cache/pickle.py b/plugins/cache/pickle.py
index 2f4b2b7b02..7dae0f2d85 100644
--- a/plugins/cache/pickle.py
+++ b/plugins/cache/pickle.py
@@ -56,6 +56,7 @@ class CacheModule(BaseFileCacheModule):
     """
     A caching module backed by pickle files.
     """
+    _persistent = False  # prevent unnecessary JSON serialization and key munging
 
     def _load(self, filepath):
         # Pickle is a binary format