diff --git a/test/mocha.opts b/test/mocha.opts
index 3d061f3d6e..c89de44e9e 100644
--- a/test/mocha.opts
+++ b/test/mocha.opts
@@ -2,3 +2,4 @@
 --ui tdd
 --check-leaks
 --globals regeneratorRuntime,i
+--inline-diffs