diff --git a/src/operations/category-chart.component.ts b/src/operations/category-chart.component.ts
index 079fa39..d041a36 100644
--- a/src/operations/category-chart.component.ts
+++ b/src/operations/category-chart.component.ts
@@ -4,7 +4,7 @@ import * as c3 from 'c3';
 
 import {
   Component, ElementRef,
-  Inject, Input, Output, EventEmitter,
+  Inject, Input, Output,
   OnInit, OnChanges
 } from '@angular/core';