diff --git a/packages/toolkit/src/query/core/buildSlice.ts b/packages/toolkit/src/query/core/buildSlice.ts
index 3343b6dc3d..68361cf7f3 100644
--- a/packages/toolkit/src/query/core/buildSlice.ts
+++ b/packages/toolkit/src/query/core/buildSlice.ts
@@ -31,8 +31,8 @@ import type {
   EndpointDefinitions,
   QueryDefinition,
 } from '../endpointDefinitions'
-import type { Patch } from 'immer'
-import { applyPatches } from 'immer'
+import { isDraft, Patch } from 'immer'
+import { applyPatches, original } from 'immer'
 import { onFocus, onFocusLost, onOffline, onOnline } from './setupListeners'
 import {
   isDocumentVisible,
@@ -208,7 +208,12 @@ export function buildSlice({
                 // Assign or safely update the cache data.
                 substate.data =
                   definitions[meta.arg.endpointName].structuralSharing ?? true
-                    ? copyWithStructuralSharing(substate.data, payload)
+                    ? copyWithStructuralSharing(
+                        isDraft(substate.data)
+                          ? original(substate.data)
+                          : substate.data,
+                        payload
+                      )
                     : payload
               }