diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 045490855..ac1ed9a14 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -1,6 +1,6 @@
 name: Build matrix
 
-on: [push, workflow_dispatch]
+on: [push, pull_request, workflow_dispatch]
 
 env:
   OPAMVERBOSE: 1
@@ -62,3 +62,4 @@ jobs:
       run: |
           eval $(opam env)
           make check-json
+          etc/ci_core_tests.sh