diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 6119a4b..21590c8 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -1,6 +1,7 @@
 name: test
 
-on: push
+on:
+  pull_request:
 
 jobs:
   linting:
@@ -22,7 +23,7 @@ jobs:
       #----------------------------------------------
       #          install and run linters
       #----------------------------------------------
-      - run: python -m pip install black flake8 isort
+      - run: python -m pip install black==23.11.0 flake8 isort
       - run: |
           flake8 .
           black . --check