diff --git a/src/test/mochitest/browser_dbg-babel-preview.js b/src/test/mochitest/browser_dbg-babel-preview.js
index 3fdaa74bbf..3662e5a1b0 100644
--- a/src/test/mochitest/browser_dbg-babel-preview.js
+++ b/src/test/mochitest/browser_dbg-babel-preview.js
@@ -1,6 +1,9 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
+// Tests for preview through Babel's compile output.
+requestLongerTimeout(3);
+
 function getCoordsFromPosition(cm, { line, ch }) {
   return cm.charCoords({ line: ~~line, ch: ~~ch });
 }
diff --git a/src/test/mochitest/browser_dbg-babel-scopes.js b/src/test/mochitest/browser_dbg-babel-scopes.js
index 0888535716..34a1458804 100644
--- a/src/test/mochitest/browser_dbg-babel-scopes.js
+++ b/src/test/mochitest/browser_dbg-babel-scopes.js
@@ -2,7 +2,7 @@
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
 // This test can be really slow on debug platforms and should be split.
-requestLongerTimeout(4);
+requestLongerTimeout(6);
 
 // Tests loading sourcemapped sources for Babel's compile output.