diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 60f0282..f9ec207 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -40,9 +40,9 @@ env:
 #
 # Granularity-only differences (same coverage, different matrix shape —
 # NOT a divergence):
-#   deb-install    — split here into per-distro legs (debian12/ubuntu24/
-#                    ubuntu26) for parallelism; local runs all distros in one
-#                    suite.
+#   deb-install    — split here into per-distro legs (debian12/debian13/
+#                    ubuntu22/ubuntu24/ubuntu26) for parallelism; local runs the
+#                    same distro set in one suite.
 #   dns-resolver   — single leg here; runs all scenarios (same as local).
 # ─────────────────────────────────────────────────────────────────────────────
 
@@ -454,6 +454,12 @@ jobs:
           - suite: deb-install-debian12
             type: deb-install
             scenario: debian12
+          - suite: deb-install-debian13
+            type: deb-install
+            scenario: debian13
+          - suite: deb-install-ubuntu22
+            type: deb-install
+            scenario: ubuntu22
           - suite: deb-install-ubuntu24
             type: deb-install
             scenario: ubuntu24
diff --git a/testing/check-ci-parity.sh b/testing/check-ci-parity.sh
index cb5ac7e..deadc6f 100755
--- a/testing/check-ci-parity.sh
+++ b/testing/check-ci-parity.sh
@@ -13,9 +13,9 @@
 #
 # Granularity-only differences folded before comparison (same coverage,
 # different matrix shape — NOT a divergence):
-#   deb-install    — GitHub splits into per-distro legs
-#                    (deb-install-debian12/ubuntu24/ubuntu26); local runs all
-#                    distros in one suite. Folded to "deb-install".
+#   deb-install    — GitHub splits into per-distro legs (deb-install-debian12/
+#                    debian13/ubuntu22/ubuntu24/ubuntu26); local runs the same
+#                    distro set in one suite. Folded to "deb-install".
 #   chaos-*        — GitHub fans each chaos scenario into its own matrix leg
 #                    (type: chaos); local runs them all via the one CHAOS_SUITES
 #                    path. The individual scenario names also differ cosmetically
diff --git a/testing/ci-local.sh b/testing/ci-local.sh
index aef519e..d9335d4 100755
--- a/testing/ci-local.sh
+++ b/testing/ci-local.sh
@@ -50,7 +50,8 @@
 # Granularity-only differences (same coverage, different matrix shape —
 # NOT a divergence):
 #   deb-install    — local runs all distros sequentially in one suite; GitHub
-#                    splits into per-distro legs (debian12/ubuntu24/ubuntu26).
+#                    splits into per-distro legs (debian12/debian13/ubuntu22/
+#                    ubuntu24/ubuntu26 — the same distro set).
 #   dns-resolver   — single suite both sides; runs all scenarios.
 # ─────────────────────────────────────────────────────────────────────────────
 set -uo pipefail