diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index d05e3809c8..c113c76b25 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -22,11 +22,18 @@ jobs:
       WITH_ASAN: ${{ matrix.WITH_ASAN }}
       COVERALLS_REPO_TOKEN: ${{ secrets.COVERALLS_REPO_TOKEN }}
       COVERALLS_SERVICE_NAME: "GitHub Actions"
+      UPLOAD_COVERALLS: "false"
 
     steps:
       - name: Checkout repository contents
         uses: actions/checkout@v3
 
+      - name: Set RUN_COVERALLS Environment Variable
+        if: (github.event.pull_request.merged == true || github.event_name == 'push') && env.WITH_ASAN != 'true'
+        run: |
+            echo "Setting UPLOAD_COVERALLS to true"
+            echo "UPLOAD_COVERALLS=true" >>${GITHUB_ENV}
+
       - name: Build
         run: |
             docker run \
@@ -34,5 +41,5 @@ jobs:
             -e WITH_ASAN="${{ env.WITH_ASAN }}" \
             -e COVERALLS_REPO_TOKEN="${{ env.COVERALLS_REPO_TOKEN }}" \
             -e COVERALLS_SERVICE_NAME="${{ env.COVERALLS_SERVICE_NAME }}" \
-            -e EVENT_NAME="${{ github.event_name }}" \
+            -e UPLOAD_COVERALLS="${{ env.UPLOAD_COVERALLS }}" \
             -v $PWD:$PWD ubuntu:20.04 $PWD/.github/workflows/start.sh
diff --git a/ci/build.sh b/ci/build.sh
index 723e1441f4..930fb5ac0d 100755
--- a/ci/build.sh
+++ b/ci/build.sh
@@ -58,8 +58,8 @@ if [ "${WITH_ASAN:-}" = "true" ]; then
 else
     make -j4 test
 fi
-   
-if [ "${EVENT_NAME:-}" = "push" ] && [ "${WITH_ASAN:-}" != "true" ] && [ -n "${COVERALLS_REPO_TOKEN:-}" ]; then
+
+if "${UPLOAD_COVERALLS:-}" = "true" ]; then
     echo "uploading to coveralls"
     git config --global --add safe.directory "${WORK_DIR:=..}"
     ln -s ../../../src/mapparser.y build/CMakeFiles/mapserver.dir/