diff --git a/botocore/utils.py b/botocore/utils.py
index e2c5c17a00..fedc227b6c 100644
--- a/botocore/utils.py
+++ b/botocore/utils.py
@@ -3510,7 +3510,9 @@ def __getitem__(self, cache_key):
             with open(actual_key) as f:
                 return json.load(f)
         except (OSError, ValueError):
-            raise KeyError(cache_key)
+            raise KeyError(
+                f'Cache file {actual_key} may be corrupt, please delete it.'
+            )
 
     def __delitem__(self, cache_key):
         actual_key = self._convert_cache_key(cache_key)