diff --git a/.github/workflows/build-subimage.yml b/.github/workflows/build-subimage.yml
new file mode 100644
index 0000000..c076a14
--- /dev/null
+++ b/.github/workflows/build-subimage.yml
@@ -0,0 +1,41 @@
+on:
+  workflow_call:
+    inputs:
+      subimage:
+        required: true
+        type: string
+    secrets:
+      DOCKERHUB_USERNAME:
+        required: true
+      DOCKERHUB_PASSWORD:
+        required: true
+
+
+jobs:
+  build-subimage-job:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v3
+        # We are checking out explicitly, so build-push-action isn't trying
+        # to checkout the (unreachable) submodule. (Using "context" there.)
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+      -
+        name: Login to Docker Hub
+        uses: docker/login-action@v2
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      -
+        name: Build ${{ inputs.subimage }}
+        uses: docker/build-push-action@v4
+        with:
+          context: .
+          file: Dockerfile-${{ inputs.subimage }}
+          build-args:
+            DRONE_COMMIT=${{ github.sha }}
+          push: true
+          tags: quratorspk/ocrd-galley-${{ inputs.subimage }}:${{ github.sha }}
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index b6a8ab4..e41634f 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -13,63 +13,16 @@ jobs:
     strategy:
       matrix:
         subimage: ["core"]
-    runs-on: ubuntu-latest
-    # TODO reuse workflow for core + rest
-    steps:
-      -
-        name: Checkout
-        uses: actions/checkout@v3
-        # We are checking out explicitly, so build-push-action isn't trying
-        # to checkout the (unreachable) submodule. (Using "context" there.)
-      -
-        name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v2
-      # TODO data
-      -
-        name: Login to Docker Hub
-        uses: docker/login-action@v2
-        with:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
-      -
-        name: Build ${{ matrix.subimage }}
-        uses: docker/build-push-action@v4
-        with:
-          context: .
-          file: Dockerfile-${{ matrix.subimage }}
-          build-args:
-            DRONE_COMMIT=${{ github.sha }}
-          push: true
-          tags: quratorspk/ocrd-galley-${{ matrix.subimage }}:${{ github.sha }}
+    uses: ./.github/workflows/build-subimage.yml
+    with:
+      subimage: ${{ matrix.subimage }}
+    secrets: inherit
 
   build-rest:
-    needs: build-core
     strategy:
       matrix:
         subimage: ["dinglehopper"]
-    runs-on: ubuntu-latest
-    steps:
-      -
-        name: Checkout
-        uses: actions/checkout@v3
-        # We are checking out explicitly, so build-push-action isn't trying
-        # to checkout the (unreachable) submodule. (Using "context" there.)
-      -
-        name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v2
-      -
-        name: Login to Docker Hub
-        uses: docker/login-action@v2
-        with:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
-      -
-        name: Build ${{ matrix.subimage }}
-        uses: docker/build-push-action@v4
-        with:
-          context: .
-          file: Dockerfile-${{ matrix.subimage }}
-          build-args:
-            DRONE_COMMIT=${{ github.sha }}
-          push: true
-          tags: quratorspk/ocrd-galley-${{ matrix.subimage }}:${{ github.sha }}
+    uses: ./.github/workflows/build-subimage.yml
+    with:
+      subimage: ${{ matrix.subimage }}
+    secrets: inherit