diff --git a/src/keeper/Event.ts b/src/keeper/Event.ts
index f4c59ee..39d9401 100644
--- a/src/keeper/Event.ts
+++ b/src/keeper/Event.ts
@@ -4,7 +4,7 @@ import Web3Provider from "./Web3Provider"
 
 export default class Event {
 
-    private poller
+    private poller = null
     private lastBlock: number = 0
     private interval: number = 200
 
@@ -15,7 +15,8 @@ export default class Event {
     }
 
     public stopListen() {
-        clearTimeout(this.poller)
+        clearInterval(this.poller)
+        this.poller = null
     }
 
     public async listen(callback: any) {
diff --git a/test/keeper/Event.test.ts b/test/keeper/Event.test.ts
index eadbe19..a0f06a7 100644
--- a/test/keeper/Event.test.ts
+++ b/test/keeper/Event.test.ts
@@ -41,6 +41,7 @@ describe("EventListener", () => {
                 assert(events)
                 assert(events.length === 2)
                 done()
+                EventListener.unsubscribe(event)
             })
 
             const {market} = keeper
diff --git a/test/keeper/EventListener.test.ts b/test/keeper/EventListener.test.ts
index 3634595..bc3eb88 100644
--- a/test/keeper/EventListener.test.ts
+++ b/test/keeper/EventListener.test.ts
@@ -41,6 +41,7 @@ describe("EventListener", () => {
             const countAfter = EventListener.count()
             assert(countBefore + 1 === countAfter, `${countBefore}${countAfter}`)
 
+            EventListener.unsubscribe(event)
             done()
         })
     })