diff --git a/.github/workflows/build_e2xgrader_images.yml b/.github/workflows/build_e2xgrader_images.yml
index 73a20b8..e38a156 100644
--- a/.github/workflows/build_e2xgrader_images.yml
+++ b/.github/workflows/build_e2xgrader_images.yml
@@ -76,6 +76,9 @@ jobs:
         id: print_image_tag
         run: |
           echo ${{ steps.set_image_tag.outputs.image_tag }}
+      - id: lower-repo
+        run: |
+          echo "repository=${GITHUB_REPOSITORY@L}" >> $GITHUB_OUTPUT
       - name: Login to ghcr.io
         if: ${{ inputs.registry == 'ghcr.io' }}
         uses: docker/login-action@v3
@@ -97,7 +100,7 @@ jobs:
         with:
           context: images/e2xgrader-notebook
           push: ${{ inputs.push }}
-          tags: ${{ inputs.registry }}/${{ github.repository }}/${{ steps.set_image_tag.outputs.image_tag }}
+          tags: ${{ inputs.registry }}/${{ steps.lower-repo.outputs.repository }}/${{ steps.set_image_tag.outputs.image_tag }}
           build-args: |
             IMAGE_SOURCE=${{ inputs.base_image_name }}:${{ inputs.base_image_tag }}
             E2XGRADER_MODE=${{ matrix.e2xgrader_mode }}
diff --git a/.github/workflows/build_image.yml b/.github/workflows/build_image.yml
index b9cee85..5d1d2e6 100644
--- a/.github/workflows/build_image.yml
+++ b/.github/workflows/build_image.yml
@@ -53,6 +53,9 @@ jobs:
       - name: Print the base image
         run: |
           echo "The base image to build from is ${{ inputs.base_image_name }}:${{ inputs.base_image_tag }}"
+      - id: lower-repo
+        run: |
+          echo "repository=${GITHUB_REPOSITORY@L}" >> $GITHUB_OUTPUT
       - name: Check if files changed
         if: ${{ ! inputs.force_build }}
         uses: dorny/paths-filter@v3
@@ -82,7 +85,7 @@ jobs:
         with:
           context: images/${{ inputs.image_name }}
           push: ${{ inputs.push }}
-          tags: ${{ inputs.registry }}/${{ github.repository }}/${{ inputs.image_name }}:${{ inputs.image_tag }}
+          tags: ${{ inputs.registry }}/${{ steps.lower-repo.outputs.repository }}/${{ inputs.image_name }}:${{ inputs.image_tag }}
           build-args: |
             IMAGE_SOURCE=${{ inputs.base_image_name }}:${{ inputs.base_image_tag }}
       - name: List images