1 files changed, 1 insertions, 1 deletions
diff --git a/devtools/shared/heapsnapshot/tests/xpcshell/heap-snapshot-worker.js b/devtools/shared/heapsnapshot/tests/xpcshell/heap-snapshot-worker.js
index a79f442193..dc70046562 100644
--- a/devtools/shared/heapsnapshot/tests/xpcshell/heap-snapshot-worker.js
+++ b/devtools/shared/heapsnapshot/tests/xpcshell/heap-snapshot-worker.js
@@ -7,7 +7,7 @@
 
 console.log("Initializing worker.");
 
-self.onmessage = ex => {
+self.onmessage = () => {
   console.log("Starting test.");
   try {
     ok(ChromeUtils, "Should have access to ChromeUtils in a worker.");