diff --git a/src/tanstack-query.ts b/src/tanstack-query.ts
index 953fe4a23db3c6a3162e6a1b4f1b46478270de47..fd1f1a91a5845f211a9e8f2d62fa8e3351460fda 100644
--- a/src/tanstack-query.ts
+++ b/src/tanstack-query.ts
@@ -47,10 +47,10 @@ class TanstackQueryOptimisticHelpers {
    * Set the entire query data.
    * If the query doesn't exist, the new query is created.
    */
-  set<Data>(
+  set = <Data>(
     queryKey: QueryKeyAndFn<Data>,
     value: Data | ((prev: Data | undefined) => Data | undefined),
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
 
     const newValue = typeof value === "function"
@@ -68,16 +68,16 @@ class TanstackQueryOptimisticHelpers {
         this.#set(queryKey, prev);
       }
     });
-  }
+  };
 
   /**
    * Update the entire query data.
    * If the query doesn't exist, it cancels
    */
-  updateExisting<Data>(
+  updateExisting = <Data>(
     queryKey: QueryKeyAndFn<Data>,
     value: Data | ((prev: Data) => Data),
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev) return;
 
@@ -89,14 +89,14 @@ class TanstackQueryOptimisticHelpers {
     this.#onRestore(() => {
       this.#set(queryKey, prev);
     });
-  }
+  };
 
   /**
    * Mark a query as changed and schedule a refetch.
    * Does not modify any data.
    * If the query doesn't exist, the updater is skipped.
    */
-  refetchOnSettled(queryKey: QueryKeyAndFn) {
+  refetchOnSettled = (queryKey: QueryKeyAndFn) => {
     if (!queryKey.queryFn) return;
     const state = this.#client.getQueryCache().find({
       queryKey: queryKey.queryKey,
@@ -109,19 +109,19 @@ class TanstackQueryOptimisticHelpers {
         await this.#client.invalidateQueries(queryKey);
       });
     } catch { /* Ignore expiry */ }
-  }
+  };
 
   /**
    * Set a property at an object path.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  objSet<Data extends object, const Path extends AllObjectPaths<Data>>(
+  objSet = <Data extends object, const Path extends AllObjectPaths<Data>>(
     queryKey: QueryKeyAndFn<Data>,
     path: Path,
     value:
       | Exclude<GetObjectPath<Data, Path>, Function>
       | ((prev: GetObjectPath<Data, Path>) => GetObjectPath<Data, Path>),
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev) return;
     const { value: original, exists } = getPath(prev, path);
@@ -145,20 +145,20 @@ class TanstackQueryOptimisticHelpers {
     this.#onRestore(() => {
       this.#set(queryKey, (obj) => obj ? setPath(obj, path, original) : obj);
     });
-  }
+  };
 
   /**
    * Increment a numeric property at an object path.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  objIncrement<
+  objIncrement = <
     Data extends object,
     const Path extends AllObjectPaths<Data>,
   >(
     queryKey: QueryKeyAndFn<Data>,
     path: Path,
     amount: number = 1,
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev) return;
     const { value: original, exists } = getPath(prev, path);
@@ -171,20 +171,20 @@ class TanstackQueryOptimisticHelpers {
     this.#onRestore(() => {
       this.#set(queryKey, (obj) => obj ? setPath(obj, path, original) : obj);
     });
-  }
+  };
 
   /**
    * Decrement a numeric property at an object path.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  objDecrement<
+  objDecrement = <
     Data extends object,
     const Path extends AllObjectPaths<Data>,
   >(
     queryKey: QueryKeyAndFn<Data>,
     path: Path,
     amount: number = 1,
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev) return;
     const { value: original, exists } = getPath(prev, path);
@@ -197,16 +197,16 @@ class TanstackQueryOptimisticHelpers {
     this.#onRestore(() => {
       this.#set(queryKey, (obj) => obj ? setPath(obj, path, original) : obj);
     });
-  }
+  };
 
   /**
    * Toggle a boolean property at an object path.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  objToggle<Data extends object, const Path extends AllObjectPaths<Data>>(
+  objToggle = <Data extends object, const Path extends AllObjectPaths<Data>>(
     queryKey: QueryKeyAndFn<Data>,
     path: Path,
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev) return;
     const { value: original, exists } = getPath(prev, path);
@@ -219,17 +219,17 @@ class TanstackQueryOptimisticHelpers {
     this.#onRestore(() => {
       this.#set(queryKey, (obj) => obj ? setPath(obj, path, original) : obj);
     });
-  }
+  };
 
   /**
    * Shallow merge multiple properties at an object path.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  objSetMany<Data extends object, const Path extends AllObjectPaths<Data>>(
+  objSetMany = <Data extends object, const Path extends AllObjectPaths<Data>>(
     queryKey: QueryKeyAndFn<Data>,
     path: Path,
     updates: Partial<GetObjectPath<Data, Path>>,
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev) return;
     const { value: original, exists } = getPath(prev, path);
@@ -248,13 +248,13 @@ class TanstackQueryOptimisticHelpers {
     this.#onRestore(() => {
       this.#set(queryKey, (obj) => obj ? setPath(obj, path, original) : obj);
     });
-  }
+  };
 
   /**
    * Push item(s) to the end of an array at an object path.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  objArrayPush<
+  objArrayPush = <
     Data extends object,
     const Path extends AllObjectPaths<Data>,
   >(
@@ -262,7 +262,7 @@ class TanstackQueryOptimisticHelpers {
     path: Path,
     ...items: GetObjectPath<Data, Path> extends Array<infer T> ? T[]
       : never
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev) return;
     const { value: original, exists } = getPath(prev, path);
@@ -276,13 +276,13 @@ class TanstackQueryOptimisticHelpers {
     this.#onRestore(() => {
       this.#set(queryKey, (obj) => obj ? setPath(obj, path, original) : obj);
     });
-  }
+  };
 
   /**
    * Add item(s) to the beginning of an array at an object path.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  objArrayUnshift<
+  objArrayUnshift = <
     Data extends object,
     const Path extends AllObjectPaths<Data>,
   >(
@@ -290,7 +290,7 @@ class TanstackQueryOptimisticHelpers {
     path: Path,
     ...items: GetObjectPath<Data, Path> extends Array<infer T> ? T[]
       : never
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev) return;
     const { value: original, exists } = getPath(prev, path);
@@ -304,13 +304,13 @@ class TanstackQueryOptimisticHelpers {
     this.#onRestore(() => {
       this.#set(queryKey, (obj) => obj ? setPath(obj, path, original) : obj);
     });
-  }
+  };
 
   /**
    * Remove items from an array that match `filter`.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  objArrayRemove<
+  objArrayRemove = <
     Data extends object,
     const Path extends AllObjectPaths<Data>,
   >(
@@ -320,7 +320,7 @@ class TanstackQueryOptimisticHelpers {
       item: GetObjectPath<Data, Path> extends Array<infer T> ? T : never,
       index: number,
     ) => boolean,
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev) return;
     const { value: original, exists } = getPath(prev, path);
@@ -335,13 +335,13 @@ class TanstackQueryOptimisticHelpers {
       // TODO: splice items back in case original changed
       this.#set(queryKey, (obj) => obj ? setPath(obj, path, original) : obj);
     });
-  }
+  };
 
   /**
    * Filter items to just include items that match `filter`. This is the inverse of `objArrayRemove`
    * If the query or path doesn't exist, the updater is skipped.
    */
-  objArrayFilter<
+  objArrayFilter = <
     Data extends object,
     const Path extends AllObjectPaths<Data>,
   >(
@@ -351,7 +351,7 @@ class TanstackQueryOptimisticHelpers {
       item: GetObjectPath<Data, Path> extends Array<infer T> ? T : never,
       index: number,
     ) => boolean,
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev) return;
     const { value: original, exists } = getPath(prev, path);
@@ -366,13 +366,13 @@ class TanstackQueryOptimisticHelpers {
       // TODO: splice items back in case original changed
       this.#set(queryKey, (obj) => obj ? setPath(obj, path, original) : obj);
     });
-  }
+  };
 
   /**
    * Update items in an array that match a predicate.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  objArrayUpdate<
+  objArrayUpdate = <
     Data extends object,
     const Path extends AllObjectPaths<Data>,
   >(
@@ -387,7 +387,7 @@ class TanstackQueryOptimisticHelpers {
         item: GetObjectPath<Data, Path> extends Array<infer T> ? T : never,
       ) => GetObjectPath<Data, Path> extends Array<infer T> ? T : never;
     },
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev) return;
     const { value: original, exists } = getPath(prev, path);
@@ -402,13 +402,13 @@ class TanstackQueryOptimisticHelpers {
       // TODO: splice items back in case original changed
       this.#set(queryKey, (obj) => obj ? setPath(obj, path, original) : obj);
     });
-  }
+  };
 
   /**
    * Insert item(s) at a specific index in an array.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  objArrayInsertIndex<
+  objArrayInsertIndex = <
     Data extends object,
     const Path extends AllObjectPaths<Data>,
   >(
@@ -417,7 +417,7 @@ class TanstackQueryOptimisticHelpers {
     index: number,
     ...items: GetObjectPath<Data, Path> extends Array<infer T> ? T[]
       : never
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev) return;
     const { value: original, exists } = getPath(prev, path);
@@ -436,13 +436,13 @@ class TanstackQueryOptimisticHelpers {
       // TODO: splice items back in case original changed
       this.#set(queryKey, (obj) => obj ? setPath(obj, path, original) : obj);
     });
-  }
+  };
 
   /**
    * Push item(s) to the end of an array at an object path.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  arrayPush<Data>(queryKey: QueryKeyAndFn<Data[] | null>, ...items: Data[]) {
+  arrayPush = <Data>(queryKey: QueryKeyAndFn<Data[] | null>, ...items: Data[]) => {
     const prev = this.#get(queryKey);
     if (!prev || !Array.isArray(prev)) return;
 
@@ -454,13 +454,13 @@ class TanstackQueryOptimisticHelpers {
         (old) => old ? old.filter((x) => !items.includes(x)) : old,
       );
     });
-  }
+  };
 
   /**
    * Add item(s) to the beginning of an array at an object path.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  arrayUnshift<Data>(queryKey: QueryKeyAndFn<Data[] | null>, ...items: Data[]) {
+  arrayUnshift = <Data>(queryKey: QueryKeyAndFn<Data[] | null>, ...items: Data[]) => {
     const prev = this.#get(queryKey);
     if (!prev || !Array.isArray(prev)) return;
 
@@ -472,19 +472,19 @@ class TanstackQueryOptimisticHelpers {
         (old) => old ? old.filter((x) => !items.includes(x)) : old,
       );
     });
-  }
+  };
 
   /**
    * Remove items from an array that match a `filter`.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  arrayRemove<Data>(
+  arrayRemove = <Data>(
     queryKey: QueryKeyAndFn<Data[] | null>,
     filter: (
       item: Data,
       index: number,
     ) => boolean,
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev || !Array.isArray(prev)) return;
 
@@ -494,19 +494,19 @@ class TanstackQueryOptimisticHelpers {
       // TODO: splice items back in case original changed
       this.#set(queryKey, prev);
     });
-  }
+  };
 
   /**
    * Filter items to just include items that match `filter`. This is the inverse of `arrayRemove`
    * If the query or path doesn't exist, the updater is skipped.
    */
-  arrayFilter<Data>(
+  arrayFilter = <Data>(
     queryKey: QueryKeyAndFn<Data[] | null>,
     filter: (
       item: Data,
       index: number,
     ) => boolean,
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev || !Array.isArray(prev)) return;
 
@@ -516,13 +516,13 @@ class TanstackQueryOptimisticHelpers {
       // TODO: splice items back in case original changed
       this.#set(queryKey, prev);
     });
-  }
+  };
 
   /**
    * Update items in an array that match a `filter`.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  arrayUpdate<Data>(
+  arrayUpdate = <Data>(
     queryKey: QueryKeyAndFn<Data[] | null>,
     {
       filter,
@@ -531,7 +531,7 @@ class TanstackQueryOptimisticHelpers {
       filter?: (item: Data, index: number) => boolean;
       update: (item: Data) => Data;
     },
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev || !Array.isArray(prev)) return;
 
@@ -541,17 +541,17 @@ class TanstackQueryOptimisticHelpers {
       // TODO: splice items back in case original changed
       this.#set(queryKey, prev);
     });
-  }
+  };
 
   /**
    * Insert item(s) at a specific index in an array.
    * If the query or path doesn't exist, the updater is skipped.
    */
-  arrayInsertIndex<Data>(
+  arrayInsertIndex = <Data>(
     queryKey: QueryKeyAndFn<Data[] | null>,
     index: number,
     ...items: Data[]
-  ) {
+  ) => {
     const prev = this.#get(queryKey);
     if (!prev || !Array.isArray(prev)) return;
 
@@ -565,12 +565,12 @@ class TanstackQueryOptimisticHelpers {
       // TODO: splice items back in case original changed
       this.#set(queryKey, prev);
     });
-  }
+  };
 
   /**
    * Remove a query from the cache entirely.
    */
-  removeQuery(queryKey: QueryKeyAndFn) {
+  removeQuery = (queryKey: QueryKeyAndFn) => {
     const prev = this.#get(queryKey);
     if (!prev) return;
 
@@ -578,7 +578,7 @@ class TanstackQueryOptimisticHelpers {
     this.#onRestore(() => {
       this.#set(queryKey, prev);
     });
-  }
+  };
 }
 
 export function queryClientOptimisticHelpers(
diff --git a/test/tanstack-query-helpers.test.ts b/test/tanstack-query-helpers.test.ts
index e4bff6b103aca0388fafd58b2c9bc4dba7a66312..0ea3486d5b520a7411144c409aefd6b0b47fce89 100644
--- a/test/tanstack-query-helpers.test.ts
+++ b/test/tanstack-query-helpers.test.ts
@@ -46,6 +46,23 @@ function createTestQueryClient() {
   return { client, queryTest };
 }
 
+test("helpers can be spread and retain bound this", () => {
+  const { client, queryTest } = createTestQueryClient();
+
+  const helpers = queryClientOptimisticHelpers(client)({
+    onRestore: () => {},
+    onRefetch: () => {},
+  });
+  const spreadHelpers = { ...helpers };
+
+  assertEquals(Object.keys(spreadHelpers).includes("objIncrement"), true);
+
+  spreadHelpers.objIncrement(queryTest, ["count"], 2);
+
+  const result = client.getQueryData<TestData>(queryTest.queryKey);
+  assertEquals(result?.count, 12);
+});
+
 // ============================================================================
 // set() tests
 // ============================================================================