diff --git a/.github/workflows/publish-docker.yml b/.github/workflows/publish-docker.yml
index 638e3f36..14516a66 100644
--- a/.github/workflows/publish-docker.yml
+++ b/.github/workflows/publish-docker.yml
@@ -7,8 +7,9 @@ name: Publish server Docker image
 
 on:
   push:
-    tags:
-      - "*"
+    branches: ["master"]
+  pull_request:
+    branches: ["master"]
 
 env:
   # Use docker.io for Docker Hub if empty
@@ -34,7 +35,7 @@ jobs:
       # Install the cosign tool except on PR
       # https://github.com/sigstore/cosign-installer
       - name: Install cosign
-        if: github.event_name != 'pull_request'
+        if: ${{ github.ref_type == 'tag' }}
         uses: sigstore/cosign-installer@59acb6260d9c0ba8f4a2f9d9b48431a222b68e20 #v3.5.0
         with:
           cosign-release: "v2.2.4"
@@ -48,7 +49,7 @@ jobs:
       # Login against a Docker registry except on PR
       # https://github.com/docker/login-action
       - name: Log into registry ${{ env.REGISTRY }}
-        if: github.event_name != 'pull_request'
+        if: ${{ github.ref_type == 'tag' }}
         uses: docker/login-action@343f7c4344506bcbf9b4de18042ae17996df046d # v3.0.0
         with:
           registry: ${{ env.REGISTRY }}
@@ -70,7 +71,7 @@ jobs:
         uses: docker/build-push-action@0565240e2d4ab88bba5387d719585280857ece09 # v5.0.0
         with:
           context: backend
-          push: ${{ github.event_name != 'pull_request' }}
+          push: ${{ github.ref_type == 'tag' }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           cache-from: type=gha
@@ -82,7 +83,7 @@ jobs:
       # transparency data even for private images, pass --force to cosign below.
       # https://github.com/sigstore/cosign
       - name: Sign the published Docker image
-        if: ${{ github.event_name != 'pull_request' }}
+        if: ${{ github.ref_type == 'tag' }}
         env:
           # https://docs.github.com/en/actions/security-guides/security-hardening-for-github-actions#using-an-intermediate-environment-variable
           TAGS: ${{ steps.meta.outputs.tags }}