diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 74279369..61d8e9f7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,6 +1,9 @@
 name: Python package
 
-on: [push]
+on:
+  pull_request:
+  push:
+    branches: [master]
 
 jobs:
   build:
diff --git a/.github/workflows/pre-commit.yml b/.github/workflows/pre-commit.yml
index 6b552a0d..3f9863b2 100644
--- a/.github/workflows/pre-commit.yml
+++ b/.github/workflows/pre-commit.yml
@@ -2,7 +2,10 @@
 # This GitHub Action assumes that the repo contains a valid .pre-commit-config.yaml file.
 ---
 name: pre-commit
-on: [push]
+on:
+  pull_request:
+  push:
+    branches: [master]
 
 permissions:
   contents: read
diff --git a/.github/workflows/python-package-conda.yml b/.github/workflows/python-package-conda.yml
index 9d45abb2..aec0afe1 100644
--- a/.github/workflows/python-package-conda.yml
+++ b/.github/workflows/python-package-conda.yml
@@ -1,6 +1,9 @@
 name: Python Package using Conda
 
-on: [push]
+on:
+  pull_request:
+  push:
+    branches: [master]
 
 jobs:
   build-linux: