diff --git a/.github/workflows/unit-test.yml b/.github/workflows/unit-test.yml
index 4282a037113eb..5853f8fcc7a51 100644
--- a/.github/workflows/unit-test.yml
+++ b/.github/workflows/unit-test.yml
@@ -80,9 +80,29 @@ jobs:
                   echo "previous-wordpress-version=${PREVIOUS_WP_VERSION}" >> $GITHUB_OUTPUT
                   rm versions.json
 
+    build-assets:
+        name: Build JavaScript assets for PHP unit tests
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633 # v4.1.2
+              with:
+                  show-progress: ${{ runner.debug == '1' && 'true' || 'false' }}
+
+            - name: Setup Node.js and install dependencies
+              uses: ./.github/setup-node
+
+            - name: Run build scripts
+              run: npm run build
+
+            - name: Upload built JavaScript assets
+              uses: actions/upload-artifact@5d5d22a31266ced268874388b861e4b58bb5c2f3 # v4.3.1
+              with:
+                  name: build-assets
+                  path: ./build/
+
     test-php:
         name: PHP ${{ matrix.php }}${{ matrix.multisite && ' multisite' || '' }}${{ matrix.wordpress != '' && format( ' (WP {0}) ', matrix.wordpress ) || '' }} on ubuntu-latest
-        needs: compute-previous-wordpress-version
+        needs: [compute-previous-wordpress-version, build-assets]
         runs-on: ubuntu-latest
         timeout-minutes: 20
         if: ${{ github.repository == 'WordPress/gutenberg' || github.event_name == 'pull_request' }}
@@ -152,8 +172,11 @@ jobs:
               with:
                   custom-cache-suffix: $(/bin/date -u --date='last Mon' "+%F")
 
-            - name: Npm build
-              run: npm run build
+            - name: Download built JavaScript assets
+              uses: actions/download-artifact@c850b930e6ba138125429b7e5c93fc707a7f8427 # v4.1.4
+              with:
+                  name: build-assets
+                  path: ./build
 
             - name: Docker debug information
               run: |
@@ -165,7 +188,6 @@ jobs:
                   node --version
                   curl --version
                   git --version
-                  svn --version
                   locale -a
 
             - name: Start Docker environment