diff --git a/taskcluster/ci/test/reftest.yml b/taskcluster/ci/test/reftest.yml
index ab58188e95fa..5697d48391cf 100644
--- a/taskcluster/ci/test/reftest.yml
+++ b/taskcluster/ci/test/reftest.yml
@@ -69,7 +69,7 @@ jsreftest:
     chunks:
         by-test-platform:
             android-em-4.3-arm7-api-16/debug: 100
-            android-em-7.0-x86/opt: 3
+            android-em-7.0-x86/opt: 4
             android-em.*: 40
             windows.*: 2
             windows10-64-ccov/debug: 5