diff --git a/src/CompositionHelper.test.ts b/src/CompositionHelper.test.ts
index 6cf615fe..64207fa0 100644
--- a/src/CompositionHelper.test.ts
+++ b/src/CompositionHelper.test.ts
@@ -44,9 +44,6 @@ describe('CompositionHelper', () => {
           return { offsetLeft: 0, offsetTop: 0 };
         }
       },
-      handler: (text: string) => {
-        handledText += text;
-      },
       buffer: {
         isCursorInViewport: true
       },
@@ -54,8 +51,12 @@ describe('CompositionHelper', () => {
         lineHeight: 1
       }
     } as any;
+    const coreService = new MockCoreService();
+    coreService.triggerDataEvent = (text: string) => {
+      handledText += text;
+    };
     handledText = '';
-    compositionHelper = new CompositionHelper(textarea, compositionView, terminal, new MockCharSizeService(10, 10), new MockCoreService());
+    compositionHelper = new CompositionHelper(textarea, compositionView, terminal, new MockCharSizeService(10, 10), coreService);
   });
 
   describe('Input', () => {