diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index d1e35c8..c589e7f 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -7,6 +7,7 @@
       - 'scripts/**'
       - 'LICENSE.txt'
       - 'README.md'
+  pull_request:
 
 env:
   CTEST_OUTPUT_ON_FAILURE: ON
@@ -14,6 +15,7 @@
 
 jobs:
   ci:
+    if: github.event_name == "push" || github.event.pull_request.head.repo.full_name != github.repository
     runs-on: ${{ matrix.os }}
 
     env:
@@ -202,6 +204,7 @@
         run: python3 .github/workflows/build_and_test.py ${{ runner.os }} x86 ${{ matrix.compiler }} ${{ matrix.version }}
 
   ci-min-gw:
+    if: github.event_name == "push" || github.event.pull_request.head.repo.full_name != github.repository
     runs-on: windows-latest
 
     strategy:
@@ -225,6 +228,7 @@
         run: ctest --test-dir build --no-tests=error
 
   ci-msvs:
+    if: github.event_name == "push" || github.event.pull_request.head.repo.full_name != github.repository
     runs-on: ${{ matrix.toolset == 'v143' && 'windows-2022' || 'windows-latest' }}
 
     strategy: