diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index a70829d..2f2ead4 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -6,6 +6,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     strategy:
+      max-parallel: 6
       matrix:
         python-version: [2.7, 3.4, 3.5, 3.6, 3.7, 3.8, 'pypy2', 'pypy3']