diff --git a/.github/workflows/mypy.yml b/.github/workflows/mypy.yml
index f68d3ac..6a80720 100644
--- a/.github/workflows/mypy.yml
+++ b/.github/workflows/mypy.yml
@@ -1,5 +1,8 @@
 name: Mypy
-on: workflow_dispatch
+on:
+  pull_request:
+    branches: [main]
+  workflow_dispatch:
 
 jobs:
   mypy_py3: