diff --git a/src/components/chests/chests.spec.ts b/src/components/chests/chests.spec.ts
index 3582724..b6c644c 100644
--- a/src/components/chests/chests.spec.ts
+++ b/src/components/chests/chests.spec.ts
@@ -60,6 +60,20 @@ describe('Chests', () => {
         expect(errorTrackerMock.Object.track).not.toHaveBeenCalled();
     });
 
+    it('patches doItOrigin without replacing an existing toolkit wrapper', () => {
+        setup('function toolkitWrapper() {}');
+        const wrapper = itemUse.doIt;
+        itemUse.doItOrigin = doItWithSource(
+            "function (itemId, itemCount) { EventHandler.signal('item_used', [itemId]); }",
+        );
+
+        chests.init();
+
+        expect(itemUse.doIt).toBe(wrapper);
+        expect(itemUse.doItOrigin.toString()).toContain('TW_Calc.trackChest(itemId,res);');
+        expect(errorTrackerMock.Object.track).not.toHaveBeenCalled();
+    });
+
     it('tracks an error and leaves the handler untouched when the anchor is missing', () => {
         setup("function (itemId, itemCount) { EventHandler.signal('something_else', [itemId]); }");
         const original = itemUse.doIt;
diff --git a/src/components/chests/chests.ts b/src/components/chests/chests.ts
index 366561e..7f2ea2e 100644
--- a/src/components/chests/chests.ts
+++ b/src/components/chests/chests.ts
@@ -35,7 +35,7 @@ export class Chests implements Component {
             const pos = match.index;
             const body = str.substr(0, pos) + 'TW_Calc.trackChest(itemId,res);' + str.substr(pos);
             this.logger.log('patching the chest handler...', body);
-            newStr = 'ItemUse.doIt = ' + body;
+            newStr = `ItemUse.${toolkit} = ${body}`;
             eval(newStr);
         } catch (e: unknown) {
             const error = e as Error;