diff --git a/.github/workflows/runtests.yml b/.github/workflows/runtests.yml
index 5a1665f..9b120f3 100644
--- a/.github/workflows/runtests.yml
+++ b/.github/workflows/runtests.yml
@@ -8,8 +8,8 @@ env:
 jobs:
   test:
     strategy:
+      max-parallel: 1
       matrix:
-        max-parallel: 2
         os: ["macos-latest", "windows-latest","ubuntu-20.04"]
         python-version: ["3.9.13","3.8.10","3.10","3.11","3.12"]
       fail-fast: false