diff --git a/.fprettify.ini b/.fprettify.ini
index 424aac784..25d1473bd 100644
--- a/.fprettify.ini
+++ b/.fprettify.ini
@@ -9,3 +9,8 @@ whitespace = 2
 enable-decl = true
 enable-replacements = true
 c-relations = true
+
+# Hack to stop fprettify formatting CUDA-style chevrons from <<< to < < <
+# We just ignore all files calling kernels:
+# TODO delete me when relevant PR for fprettify is merged: https://github.com/pseewald/fprettify/pull/162
+exclude = ["exec_dist.f90"]
diff --git a/.github/workflows/build_and_test.yml b/.github/workflows/build_and_test.yml
index 1e20c5c94..00b61cf63 100644
--- a/.github/workflows/build_and_test.yml
+++ b/.github/workflows/build_and_test.yml
@@ -1,7 +1,10 @@
 name: Run unit tests
 
 on:
-  push:
+  pull_request:
+    paths:
+      - 'src/**'
+      - 'tests/**'
 
 jobs:
   unit-tests:
@@ -10,7 +13,7 @@ jobs:
       OMPI_VERSION: 4.1.5
     steps:
 
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     # We don't want to build openmpi each time this workflow is
     # run. Setup caching of OpenMPI after it is built and installed.
@@ -18,7 +21,7 @@ jobs:
     # actions docs.
     - name: Cache OpenMPI
       id: cache-openmpi
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: openmpi-${{ env.OMPI_VERSION }}/installed
         key: openmpi-${{ env.OMPI_VERSION }}
diff --git a/.github/workflows/check_commit_messages.sh b/.github/workflows/check_commit_messages.sh
deleted file mode 100644
index 49a535a6d..000000000
--- a/.github/workflows/check_commit_messages.sh
+++ /dev/null
@@ -1,10 +0,0 @@
-#!/bin/bash
-
-BASE_REF=$1
-REF=$2
-
-for commit in $(git rev-list $BASE_REF..$REF)
-do
-    echo "Checking commit $commit"
-    git cat-file commit $commit | sed '1,/^$/d' | python githooks/commit-msg
-done
diff --git a/.github/workflows/check_policies.yml b/.github/workflows/check_policies.yml
index 6af9e9462..892ef34b0 100644
--- a/.github/workflows/check_policies.yml
+++ b/.github/workflows/check_policies.yml
@@ -1,24 +1,17 @@
 name: check-policies
-on: [push]
+
+on: [pull_request]
+
 jobs:
-  check-commit-messages:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          # Checkout with full history, not just latest revision.
-          fetch-depth: 0
-      - uses: actions/setup-python@v4
-      - run: |
-          bash .github/workflows/check_commit_messages.sh \
-            ${{ github.event.before }} ${{ github.event.after }}
   check-formatting:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/setup-python@v4
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.10'
       - run: pip install fprettify
       - run: fprettify --config .fprettify.ini --diff --recursive src
-      - run: test -z "$($FPRETTIFY_COMMAND)"
+      - run: if [[ ! -z "$($FPRETTIFY_COMMAND)" ]]; then echo "::warning::Code formatting issues detected. See log for details."; fi
         env:
           FPRETTIFY_COMMAND: fprettify --config .fprettify.ini --diff --recursive src