diff --git a/src/fastmcp/contrib/middleware/caching/elasticsearch/elasticsearch_cache.py b/src/fastmcp/contrib/middleware/caching/elasticsearch/elasticsearch_cache.py
index 4267acaf2..973b4fc00 100644
--- a/src/fastmcp/contrib/middleware/caching/elasticsearch/elasticsearch_cache.py
+++ b/src/fastmcp/contrib/middleware/caching/elasticsearch/elasticsearch_cache.py
@@ -31,18 +31,13 @@ DEFAULT_MAPPING = {
         "value": {
             "type": "keyword",
             "index": False,
+            "doc_values": False,
+            "ignore_above": 256,
         },
     },
 }
 
 
-class SetEncoder(json.JSONEncoder):
-    def default(self, obj):
-        if isinstance(obj, set):
-            return list(obj)
-        return json.JSONEncoder.default(self, obj)
-
-
 class ElasticsearchCache(CacheProtocol):
     """A cache client that uses Elasticsearch."""
 
@@ -111,7 +106,7 @@ class ElasticsearchCache(CacheProtocol):
             collection=cache_entry.collection, key=cache_entry.key
         )
 
-        document = json.loads(cache_entry.model_dump_json())
+        document = json.loads(cache_entry.model_dump_json(serialize_as_any=True))
 
         document["value"] = json.dumps(document["value"])
 
diff --git a/src/fastmcp/server/middleware/caching.py b/src/fastmcp/server/middleware/caching.py
index d4a223a58..d2cd0b4e6 100644
--- a/src/fastmcp/server/middleware/caching.py
+++ b/src/fastmcp/server/middleware/caching.py
@@ -65,9 +65,7 @@ class BaseCacheEntry(BaseModel, ABC):
     )
 
     created_at: datetime = Field(default_factory=lambda: datetime.now(tz=timezone.utc))
-    value: CachableValueTypes
 
-    collection: str
     key: str
 
     ttl: int
@@ -265,12 +263,12 @@ class CacheProtocol(Protocol):
         self,
         collection: str,
         key: str,
-    ) -> BaseCacheEntry | None:
+    ) -> CacheEntryTypes | None:
         """Get a cache entry from the cache."""
 
     async def set_entry(
         self,
-        cache_entry: BaseCacheEntry,
+        cache_entry: CacheEntryTypes,
     ) -> None:
         """Set a value in the cache using the collection and key."""
 
@@ -307,7 +305,7 @@ class DiskCache(CacheProtocol):
             directory=path, size_limit=size_limit
         )
 
-    async def get_entry(self, collection: str, key: str) -> BaseCacheEntry | None:
+    async def get_entry(self, collection: str, key: str) -> CacheEntryTypes | None:
         collection_key: str = self.make_collection_key(collection=collection, key=key)
 
         cache_entry = self._cache.get(key=collection_key)
@@ -319,7 +317,7 @@ class DiskCache(CacheProtocol):
 
     async def set_entry(
         self,
-        cache_entry: BaseCacheEntry,
+        cache_entry: CacheEntryTypes,
     ) -> None:
         collection_key: str = self.make_collection_key(
             collection=cache_entry.collection, key=cache_entry.key
@@ -356,20 +354,22 @@ class InMemoryCache(CacheProtocol):
             max_entries: The maximum number of entries to store in the cache. Defaults to 1000.
         """
         self.max_entries = max_entries
-        self._cache = MemoryCacheClient(
+        self._cache: MemoryCacheClient[Any, CacheEntryTypes] = MemoryCacheClient[
+            Any, CacheEntryTypes
+        ](
             maxsize=max_entries,
             ttu=_memory_cache_ttu,
             getsizeof=_memory_cache_getsizeof,
         )
 
-    async def get_entry(self, collection: str, key: str) -> BaseCacheEntry | None:
-        collection_key = self.make_collection_key(collection=collection, key=key)
+    async def get_entry(self, collection: str, key: str) -> CacheEntryTypes | None:
+        collection_key: str = self.make_collection_key(collection=collection, key=key)
 
         return self._cache.get(collection_key)
 
     async def set_entry(
         self,
-        cache_entry: BaseCacheEntry,
+        cache_entry: CacheEntryTypes,
     ) -> None:
         collection_key: str = self.make_collection_key(
             collection=cache_entry.collection, key=cache_entry.key
@@ -483,7 +483,7 @@ class MethodSettings(TypedDict):
 
 MethodSettingsType = TypeVar("MethodSettingsType", bound=SharedMethodSettings)
 
-MCP_METHOD_TO_CACHE_ENTRY_TYPE: dict[str, type[BaseCacheEntry]] = {
+MCP_METHOD_TO_CACHE_ENTRY_TYPE: dict[str, type[CacheEntryTypes]] = {
     "tools/list": ListToolsCacheEntry,
     "tools/call": ToolResultCacheEntry,
     "resources/list": ListResourcesCacheEntry,
@@ -746,10 +746,10 @@ class ResponseCachingMiddleware(Middleware):
 
         ttl: int = self._get_cache_ttl(context=context)
 
-        cache_entry: BaseCacheEntry = MCP_METHOD_TO_CACHE_ENTRY_TYPE[collection](
-            collection=collection,
+        cache_entry: CacheEntryTypes = MCP_METHOD_TO_CACHE_ENTRY_TYPE[collection](
+            collection=collection,  # pyright: ignore[reportArgumentType]
             key=key,
-            value=value,
+            value=value,  # pyright: ignore[reportArgumentType]
             ttl=ttl,
         )