diff --git a/.github/workflows/gitlab-helper.yml b/.github/workflows/gitlab-helper.yml
index 16710c5713..9dc8ff5550 100644
--- a/.github/workflows/gitlab-helper.yml
+++ b/.github/workflows/gitlab-helper.yml
@@ -1,6 +1,7 @@
-# This workflow runs on PRs and the merge queue and is only responsible for
-# starting the "Start GitLab CI" workflow in a way that makes it possible to
-# use secrets.
+# This workflow runs on PRs and the merge queue and is responsible for starting
+# the "Start GitLab CI" workflow in a way that makes it possible to use
+# secrets. The workflow first runs source preparation to make sure that the
+# gitlab-ci.yml is up to date.
 ---
 name: GitLab
 
@@ -12,6 +13,39 @@ on:
   merge_group:
 
 jobs:
+  prepare:
+    name: "🔍 Check source preparation"
+    runs-on: ubuntu-latest
+    steps:
+
+      - name: Set up Go 1.20
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.20"
+        id: go
+
+      - name: Check out code into the Go module directory
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+
+      - name: Install dependencies
+        run: |
+          sudo apt update
+          sudo apt install -y libgpgme-dev libbtrfs-dev libdevmapper-dev
+
+      - name: Check that source has been prepared
+        run: |
+          ./tools/prepare-source.sh
+          if [ -n "$(git status --porcelain)" ]; then
+            echo
+            echo "Please include these changes in your branch: "
+            git status -vv
+            exit "1"
+          else
+            exit "0"
+          fi
+
   gitlab-ci-helper:
     name: "Gitlab CI trigger helper"
     runs-on: ubuntu-latest
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 40852a0210..64f00f9af8 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -136,34 +136,6 @@ jobs:
           version: v1.54.2
           args: --verbose --timeout 5m0s
 
-  prepare:
-    name: "🔍 Check source preparation"
-    runs-on: ubuntu-latest
-    steps:
-
-      - name: Set up Go 1.20
-        uses: actions/setup-go@v5
-        with:
-          go-version: "1.20"
-        id: go
-
-      - name: Check out code into the Go module directory
-        uses: actions/checkout@v4
-        with:
-          ref: ${{ github.event.pull_request.head.sha }}
-
-      - name: Check that source has been prepared
-        run: |
-          ./tools/prepare-source.sh
-          if [ -n "$(git status --porcelain)" ]; then
-            echo
-            echo "Please include these changes in your branch: "
-            git status -vv
-            exit "1"
-          else
-            exit "0"
-          fi
-
   shellcheck:
     name: "🐚 Shellcheck"
     runs-on: ubuntu-latest