diff --git a/client/src/client/workers/test-evaluator.js b/client/src/client/workers/test-evaluator.js
index f1e3d5f7ec..ed44a8ac96 100644
--- a/client/src/client/workers/test-evaluator.js
+++ b/client/src/client/workers/test-evaluator.js
@@ -3,12 +3,11 @@ import '@babel/polyfill';
 
 const oldLog = self.console.log.bind(self.console);
 self.console.log = function proxyConsole(...args) {
-  self.__logs = [...self.__logs, ...args];
+  self.postMessage({ type: 'LOG', data: String(args) });
   return oldLog(...args);
 };
 
 onmessage = async e => {
-  self.__logs = [];
   const { script: __test, code } = e.data;
   /* eslint-disable no-unused-vars */
   const assert = chai.assert;
@@ -21,14 +20,13 @@ onmessage = async e => {
     if (typeof testResult === 'function') {
       await testResult(() => code);
     }
-    self.postMessage({ pass: true, logs: self.__logs.map(String) });
+    self.postMessage({ pass: true });
   } catch (err) {
     self.postMessage({
       err: {
         message: err.message,
         stack: err.stack
-      },
-      logs: self.__logs.map(String)
+      }
     });
     if (!(err instanceof chai.AssertionError)) {
       console.error(err);
diff --git a/client/src/templates/Challenges/redux/execute-challenge-saga.js b/client/src/templates/Challenges/redux/execute-challenge-saga.js
index b2e38edc97..8c3b43dbca 100644
--- a/client/src/templates/Challenges/redux/execute-challenge-saga.js
+++ b/client/src/templates/Challenges/redux/execute-challenge-saga.js
@@ -67,15 +67,29 @@ function* ExecuteChallengeSaga() {
   }
 }
 
+function* logToConsole(channel) {
+  yield takeEvery(channel, function*(args) {
+    yield put(updateLogs(args));
+  });
+}
+
 function* ExecuteJSChallengeSaga() {
   const files = yield select(challengeFilesSelector);
   const { code, solution } = yield call(buildJSFromFiles, files);
 
+  const consoleProxy = yield channel();
+  yield fork(logToConsole, consoleProxy);
+  const log = args => consoleProxy.put(args);
+  testWorker.on('LOG', log);
+
   const testResults = yield call(executeTests, {
     testRunner: testWorker,
     code,
     solution
   });
+
+  testWorker.remove('LOG', log);
+  consoleProxy.close();
   return testResults;
 }
 
@@ -86,12 +100,6 @@ function createTestFrame(state, ctx, proxyLogger) {
   }).then(() => console.log('Frame ready'));
 }
 
-function* logToConsole(channel) {
-  yield takeEvery(channel, function*(args) {
-    yield put(updateLogs(args));
-  });
-}
-
 function* ExecuteDOMChallengeSaga() {
   const state = yield select();
   const ctx = yield call(buildFromFiles, state);
@@ -166,14 +174,11 @@ function* executeTests({ testRunner, code = '', solution = '' }) {
   for (const { text, testString } of tests) {
     const newTest = { text, testString };
     try {
-      const { pass, err, logs = [] } = yield call(
+      const { pass, err } = yield call(
         testRunner.execute,
         { script: solution + '\n' + testString, code },
         testTimeout
       );
-      for (const log of logs) {
-        yield put(updateLogs(log));
-      }
       if (pass) {
         newTest.pass = true;
       } else {
diff --git a/client/src/templates/Challenges/utils/worker-executor.js b/client/src/templates/Challenges/utils/worker-executor.js
index 838beda2d4..e79dc26e18 100644
--- a/client/src/templates/Challenges/utils/worker-executor.js
+++ b/client/src/templates/Challenges/utils/worker-executor.js
@@ -2,6 +2,7 @@ export default class WorkerExecutor {
   constructor(workerName) {
     this.workerName = workerName;
     this.worker = null;
+    this.observers = {};
 
     this.execute = this.execute.bind(this);
     this.killWorker = this.killWorker.bind(this);
@@ -36,6 +37,13 @@ export default class WorkerExecutor {
 
       // Handle result
       worker.onmessage = e => {
+        if (e.data && e.data.type) {
+          const observers = this.observers[e.data.type] || [];
+          for (const observer of observers) {
+            observer(e.data.data);
+          }
+          return;
+        }
         clearTimeout(timeoutId);
         resolve(e.data);
       };
@@ -46,4 +54,18 @@ export default class WorkerExecutor {
       };
     });
   }
+
+  on(type, callback) {
+    const observers = this.observers[type] || [];
+    observers.push(callback);
+    this.observers[type] = observers;
+  }
+
+  remove(type, callback) {
+    const observers = this.observers[type] || [];
+    const index = observers.indexOf(callback);
+    if (index !== -1) {
+      observers.splice(index, 1);
+    }
+  }
 }