diff --git a/.github/workflows/app-build-verify.yml b/.github/workflows/app-build-verify.yml
index ff5e957d..f81b2e4d 100644
--- a/.github/workflows/app-build-verify.yml
+++ b/.github/workflows/app-build-verify.yml
@@ -186,17 +186,29 @@ jobs:
         briefcase build windows VisualStudio
         briefcase package windows VisualStudio --adhoc-sign
 
-    - name: Build Linux System project (Debian, local)
+    - name: Build Linux System project (Ubuntu, local)
       if: |
         startsWith(inputs.runner-os, 'ubuntu')
         && contains(fromJSON('["", "Linux"]'), inputs.target-platform)
         && contains(fromJSON('["", "system"]'), inputs.target-format)
+        && ${{ inputs.briefcase-template-source == '3.10' }}
       run: |
         cd tests/apps/verify-${{ inputs.framework }}
         briefcase create linux system
         briefcase build linux system
         briefcase package linux system --adhoc-sign
 
+    - name: Build Linux System project (Debian, Dockerized)
+      if: |
+        startsWith(inputs.runner-os, 'ubuntu')
+        && contains(fromJSON('["", "Linux"]'), inputs.target-platform)
+        && contains(fromJSON('["", "system"]'), inputs.target-format)
+      run: |
+        cd tests/apps/verify-${{ inputs.framework }}
+        briefcase create linux system --target debian:bullseye
+        briefcase build linux system --target debian:bullseye
+        briefcase package linux system --target debian:bullseye --adhoc-sign
+
     - name: Build Linux System project (RPM, Dockerized)
       if: |
         startsWith(inputs.runner-os, 'ubuntu')
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ef74b9ff..32e9a773 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -175,7 +175,7 @@ jobs:
     uses: ./.github/workflows/app-build-verify.yml
     with:
       # This *must* be the version of Python that is the system Python on ubuntu-latest.
-      # Otherwise native system package builds won't succeed.
+      # Otherwise native system package builds won't be included.
       python-version: "3.10"
       repository: beeware/briefcase
       runner-os: ${{ matrix.runner-os }}