diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 34bf61c2f8..9661ff9393 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -151,8 +151,14 @@ jobs:
           # this is what we push to ECR
           # we will also take semver'd tags like `1.0.0` and use them for releases
 
+          # In push & PR events we want the tag to contain the latest commit on the branch:
+          # in push events, the latest commit of the master branch is GITHUB_SHA
+          # in PR synch the latest commit of the branch is found in github.event.pull_request.head.sha instead
+
           if [ "${{ github.event_name }}" = "release" ] && [ "${{ github.event.action }}" = "released" ]; then
             echo "::set-output name=tag::${REF_ID/refs-tags-/}"
+          elif [ "${{ github.event_name }}" = "pull_request" ]; then
+            echo "::set-output name=tag::$REF_ID-${{ github.event.pull_request.head.sha }}"
           else
             echo "::set-output name=tag::$REF_ID-$GITHUB_SHA"
           fi
diff --git a/.github/workflows/pr_validate.yaml b/.github/workflows/pr_validate.yaml
index f244104d31..d704e4b892 100644
--- a/.github/workflows/pr_validate.yaml
+++ b/.github/workflows/pr_validate.yaml
@@ -140,9 +140,9 @@ jobs:
         if: steps.check-e2e-run.outputs.should-e2e-run == 'true'
         name: Get details of last commit
         run: |-
-          echo "SHA of GitHub merge commit:"
-          echo $GITHUB_SHA
-          echo "::set-output name=github_sha::$GITHUB_SHA"
+          echo "SHA of latest GitHub branch commit:"
+          echo ${{ github.event.pull_request.head.sha }}
+          echo "::set-output name=github_sha::${{ github.event.pull_request.head.sha }}"
 
           REPO_NAME=$(echo $GITHUB_REPOSITORY | awk -F '/' '{print $2}')
           echo "Repo name:"