diff --git a/.changeset/fix-persister-query-key-infer.md b/.changeset/fix-persister-query-key-infer.md
new file mode 100644
index 00000000000..e721d6dcfb9
--- /dev/null
+++ b/.changeset/fix-persister-query-key-infer.md
@@ -0,0 +1,5 @@
+---
+'@tanstack/query-core': patch
+---
+
+fix(query-core): wrap `persister`'s `TQueryKey` in `NoInfer` so that the `persister` slot no longer contributes to `TQueryKey` inference. Follow-up to #10510, which removed `NoInfer` on all three `persister` generics. Preserving `NoInfer<TQueryKey>` keeps that fix's benefit for `TQueryFnData` while preventing `TQueryKey` from widening to the augmented constraint when `Register.queryKey` is narrowed — which made `DataTag`-branded wrapper returns un-assignable in contravariant slots.
diff --git a/.changeset/query-devtools-onclose-setter-type.md b/.changeset/query-devtools-onclose-setter-type.md
new file mode 100644
index 00000000000..1e615ae3b67
--- /dev/null
+++ b/.changeset/query-devtools-onclose-setter-type.md
@@ -0,0 +1,5 @@
+---
+'@tanstack/query-devtools': patch
+---
+
+Update the devtools panel `setOnClose` callback type to return `void`.
diff --git a/packages/query-core/src/types.ts b/packages/query-core/src/types.ts
index 6e26b02746a..6cfe16484e5 100644
--- a/packages/query-core/src/types.ts
+++ b/packages/query-core/src/types.ts
@@ -231,7 +231,7 @@ export interface QueryOptions<
 > {
   /**
    * If `false`, failed queries will not retry by default.
-   * If `true`, failed queries will retry infinitely., failureCount: num
+   * If `true`, failed queries will retry infinitely.
    * If set to an integer number, e.g. 3, failed queries will retry until the failed query count meets that number.
    * If set to a function `(failureCount, error) => boolean` failed queries will retry until the function returns false.
    */
@@ -246,7 +246,7 @@ export interface QueryOptions<
    */
   gcTime?: number
   queryFn?: QueryFunction<TQueryFnData, TQueryKey, TPageParam> | SkipToken
-  persister?: QueryPersister<TQueryFnData, TQueryKey, TPageParam>
+  persister?: QueryPersister<TQueryFnData, NoInfer<TQueryKey>, TPageParam>
   queryHash?: string
   queryKey?: TQueryKey
   queryKeyHashFn?: QueryKeyHashFunction<TQueryKey>
diff --git a/packages/query-devtools/src/TanstackQueryDevtoolsPanel.tsx b/packages/query-devtools/src/TanstackQueryDevtoolsPanel.tsx
index 6294a6de659..42ee5631961 100644
--- a/packages/query-devtools/src/TanstackQueryDevtoolsPanel.tsx
+++ b/packages/query-devtools/src/TanstackQueryDevtoolsPanel.tsx
@@ -34,7 +34,7 @@ class TanstackQueryDevtoolsPanel {
   #initialIsOpen: Signal<boolean | undefined>
   #errorTypes: Signal<Array<DevtoolsErrorType> | undefined>
   #hideDisabledQueries: Signal<boolean | undefined>
-  #onClose: Signal<(() => unknown) | undefined>
+  #onClose: Signal<(() => void) | undefined>
   #Component: DevtoolsComponentType | undefined
   #theme: Signal<Theme | undefined>
   #dispose?: () => void
@@ -90,7 +90,7 @@ class TanstackQueryDevtoolsPanel {
     this.#client[1](client)
   }
 
-  setOnClose(onClose: () => unknown) {
+  setOnClose(onClose: () => void) {
     this.#onClose[1](() => onClose)
   }