diff --git a/.github/actions/setup/action.yml b/.github/actions/setup/action.yml
index 1e155cd1ac..32432b407e 100644
--- a/.github/actions/setup/action.yml
+++ b/.github/actions/setup/action.yml
@@ -28,33 +28,39 @@ runs:
       id: diff
       shell: bash
       run: |
-        echo "::set-output name=GITHUB_ACTIONS_CHANGED::$(git diff --shortstat origin/${{ github.base_ref }}..HEAD -- .github/actions .github/workflows | wc -l)"
+        previousCommit=${{ github.event.before }}
+        baseRef=${{ steps.diff.outputs.ORIGIN_BRANCH }}
+        origin=$( [[ -z $baseRef ]] && echo $previousCommit || echo "origin/$baseRef" )
 
-        echo "::set-output name=SPECS_CHANGED::$(git diff --shortstat origin/${{ github.base_ref }}..HEAD -- specs | wc -l)"
-        echo "::set-output name=COMMON_SPECS_CHANGED::$(git diff --shortstat origin/${{ github.base_ref }}..HEAD -- specs/common | wc -l)"
+        echo "::set-output name=GITHUB_ACTIONS_CHANGED::$(git diff --shortstat $origin..HEAD -- .github/actions .github/workflows | wc -l)"
 
-        echo "::set-output name=TESTS_CHANGED::$(git diff --shortstat origin/${{ github.base_ref }}..HEAD -- tests | wc -l)"
+        echo "::set-output name=SPECS_CHANGED::$(git diff --shortstat $origin..HEAD -- specs | wc -l)"
+        echo "::set-output name=COMMON_SPECS_CHANGED::$(git diff --shortstat $origin..HEAD -- specs/common | wc -l)"
 
-        echo "::set-output name=SCRIPTS_CHANGED::$(git diff --shortstat origin/${{ github.base_ref }}..HEAD -- scripts | wc -l)"
+        echo "::set-output name=TESTS_CHANGED::$(git diff --shortstat $origin..HEAD -- tests | wc -l)"
 
-        echo "::set-output name=JS_CLIENT_CHANGED::$(git diff --shortstat origin/${{ github.base_ref }}..HEAD -- clients/algoliasearch-client-javascript | wc -l)"
-        echo "::set-output name=JS_ALGOLIASEARCH_CHANGED::$(git diff --shortstat origin/${{ github.base_ref }}..HEAD -- clients/algoliasearch-client-javascript/packages/algoliasearch clients/algoliasearch-client-javascript/packages/client-search clients/algoliasearch-client-javascript/packages/client-analytics clients/algoliasearch-client-javascript/packages/client-personalization | wc -l)"
-        echo "::set-output name=JS_COMMON_CHANGED::$(git diff --shortstat origin/${{ github.base_ref }}..HEAD -- clients/algoliasearch-client-javascript/packages/client-common clients/algoliasearch-client-javascript/packages/requester-browser-xhr clients/algoliasearch-client-javascript/packages/requester-node-http | wc -l)"
-        echo "::set-output name=JS_TEMPLATE_CHANGED::$(git diff --shortstat origin/${{ github.base_ref }}..HEAD -- templates/javascript | wc -l)"
+        echo "::set-output name=SCRIPTS_CHANGED::$(git diff --shortstat $origin..HEAD -- scripts | wc -l)"
 
-        echo "::set-output name=JAVA_CLIENT_CHANGED::$(git diff --shortstat origin/${{ github.base_ref }}..HEAD -- clients/algoliasearch-client-java-2 | wc -l)"
-        echo "::set-output name=JAVA_TEMPLATE_CHANGED::$(git diff --shortstat origin/${{ github.base_ref }}..HEAD -- templates/java | wc -l)"
+        echo "::set-output name=JS_CLIENT_CHANGED::$(git diff --shortstat $origin..HEAD -- clients/algoliasearch-client-javascript | wc -l)"
+        echo "::set-output name=JS_ALGOLIASEARCH_CHANGED::$(git diff --shortstat $origin..HEAD -- clients/algoliasearch-client-javascript/packages/algoliasearch clients/algoliasearch-client-javascript/packages/client-search clients/algoliasearch-client-javascript/packages/client-analytics clients/algoliasearch-client-javascript/packages/client-personalization | wc -l)"
+        echo "::set-output name=JS_COMMON_CHANGED::$(git diff --shortstat $origin..HEAD -- clients/algoliasearch-client-javascript/packages/client-common clients/algoliasearch-client-javascript/packages/requester-browser-xhr clients/algoliasearch-client-javascript/packages/requester-node-http | wc -l)"
+        echo "::set-output name=JS_TEMPLATE_CHANGED::$(git diff --shortstat $origin..HEAD -- templates/javascript | wc -l)"
 
-        echo "::set-output name=PHP_CLIENT_CHANGED::$(git diff --shortstat origin/${{ github.base_ref }}..HEAD -- clients/algoliasearch-client-php | wc -l)"
-        echo "::set-output name=PHP_TEMPLATE_CHANGED::$(git diff --shortstat origin/${{ github.base_ref }}..HEAD -- templates/php | wc -l)"
+        echo "::set-output name=JAVA_CLIENT_CHANGED::$(git diff --shortstat $origin..HEAD -- clients/algoliasearch-client-java-2 | wc -l)"
+        echo "::set-output name=JAVA_TEMPLATE_CHANGED::$(git diff --shortstat $origin..HEAD -- templates/java | wc -l)"
+
+        echo "::set-output name=PHP_CLIENT_CHANGED::$(git diff --shortstat $origin..HEAD -- clients/algoliasearch-client-php | wc -l)"
+        echo "::set-output name=PHP_TEMPLATE_CHANGED::$(git diff --shortstat $origin..HEAD -- templates/php | wc -l)"
+
+        echo "::set-output name=ORIGIN_BRANCH::$origin"
 
     - name: Compute specs matrix
       id: spec-matrix
       shell: bash
       run: |
-        base_changed=${{ github.ref == 'refs/heads/main' || steps.diff.outputs.GITHUB_ACTIONS_CHANGED > 0 || steps.diff.outputs.SCRIPTS_CHANGED > 0 || steps.diff.outputs.COMMON_SPECS_CHANGED > 0 }}
+        base_changed=${{ steps.diff.outputs.GITHUB_ACTIONS_CHANGED > 0 || steps.diff.outputs.SCRIPTS_CHANGED > 0 || steps.diff.outputs.COMMON_SPECS_CHANGED > 0 }}
 
-        matrix=$(./scripts/ci/create-spec-matrix.sh $base_changed ${{ github.base_ref }})
+        matrix=$(./scripts/ci/create-spec-matrix.sh $base_changed ${{ steps.diff.outputs.ORIGIN_BRANCH }})
 
         if [[ $matrix == '{"client":["no-run"]}' ]]; then
           run="false"
@@ -72,10 +78,10 @@ runs:
       id: js-matrix
       shell: bash
       run: |
-        base_changed=${{ github.ref == 'refs/heads/main' || steps.diff.outputs.GITHUB_ACTIONS_CHANGED > 0 || steps.diff.outputs.COMMON_SPECS_CHANGED > 0 || steps.diff.outputs.SCRIPTS_CHANGED > 0 || steps.diff.outputs.JS_TEMPLATE_CHANGED > 0 }}
+        base_changed=${{ steps.diff.outputs.GITHUB_ACTIONS_CHANGED > 0 || steps.diff.outputs.COMMON_SPECS_CHANGED > 0 || steps.diff.outputs.SCRIPTS_CHANGED > 0 || steps.diff.outputs.JS_TEMPLATE_CHANGED > 0 }}
         algoliasearch_changed=${{ steps.diff.outputs.JS_ALGOLIASEARCH_CHANGED > 0 }}
 
-        matrix=$(./scripts/ci/create-client-matrix.sh javascript $base_changed ${{ github.base_ref }})
+        matrix=$(./scripts/ci/create-client-matrix.sh javascript $base_changed ${{ steps.diff.outputs.ORIGIN_BRANCH }})
 
         if [[ $algoliasearch_changed == 'true' || $base_changed == 'true' ]]; then
           algoliasearch_client='{"name": "algoliasearch","folder": "clients/algoliasearch-client-javascript/packages/algoliasearch"}'
@@ -108,9 +114,9 @@ runs:
       id: java-matrix
       shell: bash
       run: |
-        base_changed=${{ github.ref == 'refs/heads/main' || steps.diff.outputs.GITHUB_ACTIONS_CHANGED > 0 || steps.diff.outputs.COMMON_SPECS_CHANGED > 0 || steps.diff.outputs.SCRIPTS_CHANGED > 0 || steps.diff.outputs.JAVA_TEMPLATE_CHANGED > 0 }}
+        base_changed=${{ steps.diff.outputs.GITHUB_ACTIONS_CHANGED > 0 || steps.diff.outputs.COMMON_SPECS_CHANGED > 0 || steps.diff.outputs.SCRIPTS_CHANGED > 0 || steps.diff.outputs.JAVA_TEMPLATE_CHANGED > 0 }}
 
-        matrix=$(./scripts/ci/create-client-matrix.sh java $base_changed ${{ github.base_ref }})
+        matrix=$(./scripts/ci/create-client-matrix.sh java $base_changed ${{ steps.diff.outputs.ORIGIN_BRANCH }})
 
         if [[ $matrix == '{"client":["no-run"]}' ]]; then
           run="false"
@@ -128,9 +134,9 @@ runs:
       id: php-matrix
       shell: bash
       run: |
-        base_changed=${{ github.ref == 'refs/heads/main' || steps.diff.outputs.GITHUB_ACTIONS_CHANGED > 0 || steps.diff.outputs.COMMON_SPECS_CHANGED > 0 || steps.diff.outputs.SCRIPTS_CHANGED > 0 || steps.diff.outputs.PHP_TEMPLATE_CHANGED > 0 }}
+        base_changed=${{ steps.diff.outputs.GITHUB_ACTIONS_CHANGED > 0 || steps.diff.outputs.COMMON_SPECS_CHANGED > 0 || steps.diff.outputs.SCRIPTS_CHANGED > 0 || steps.diff.outputs.PHP_TEMPLATE_CHANGED > 0 }}
 
-        matrix=$(./scripts/ci/create-client-matrix.sh php $base_changed ${{ github.base_ref }})
+        matrix=$(./scripts/ci/create-client-matrix.sh php $base_changed ${{ steps.diff.outputs.ORIGIN_BRANCH }})
 
         if [[ $matrix == '{"client":["no-run"]}' ]]; then
           run="false"
diff --git a/scripts/ci/create-client-matrix.sh b/scripts/ci/create-client-matrix.sh
index 0d7e292157..67a9319d17 100755
--- a/scripts/ci/create-client-matrix.sh
+++ b/scripts/ci/create-client-matrix.sh
@@ -23,8 +23,8 @@ to_test='{"client": []}'
 for pair in $CLIENTS; do
     name=$(echo $pair | jq -r '.name')
     folder=$(echo $pair | jq -r '.folder')
-    spec_changed=$(git diff --shortstat origin/$BASE_BRANCH..HEAD -- specs/$name | wc -l | tr -d ' ')
-    client_changed=$(git diff --stat origin/$BASE_BRANCH..HEAD -- $folder | wc -l | tr -d ' ')
+    spec_changed=$(git diff --shortstat $BASE_BRANCH..HEAD -- specs/$name | wc -l | tr -d ' ')
+    client_changed=$(git diff --stat $BASE_BRANCH..HEAD -- $folder | wc -l | tr -d ' ')
     if [[ $BASE_CHANGED == "true" || $spec_changed != "0" || $client_changed != "0" ]]; then
         to_test=$(echo $to_test | jq --argjson pair $pair '.client |= .+ [$pair]')
     fi
diff --git a/scripts/ci/create-spec-matrix.sh b/scripts/ci/create-spec-matrix.sh
index 749ea7dbbc..96e46f1e1e 100755
--- a/scripts/ci/create-spec-matrix.sh
+++ b/scripts/ci/create-spec-matrix.sh
@@ -10,7 +10,7 @@ to_check='{"client":[]}'
 for generator in "${GENERATORS[@]}"; do
     client=${generator#*-}
     if [[ ! ${SPECS[*]} =~ $client ]]; then
-        changed=$(git diff --shortstat origin/$BASE_BRANCH..HEAD -- specs/$client | wc -l)
+        changed=$(git diff --shortstat $BASE_BRANCH..HEAD -- specs/$client | wc -l)
         SPECS+=($client)
         if [[ $BASE_CHANGED == "true" || $changed > 0 ]]; then
             to_check=$(echo $to_check | jq --arg client $client '.client |= .+ [$client]')