diff --git a/.github/actionlint.yaml b/.github/actionlint.yaml
new file mode 100644
index 0000000..1731e3e
--- /dev/null
+++ b/.github/actionlint.yaml
@@ -0,0 +1,8 @@
+self-hosted-runner:
+  # Despite the key name, these are GitHub-hosted labels: no actionlint
+  # release (up to 1.7.12) knows ubuntu-26.04 yet, so without this entry the
+  # linters job rejects every job with "label is unknown". Drop it once
+  # actionlint ships the labels.
+  labels:
+    - ubuntu-26.04
+    - ubuntu-26.04-arm
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index aca2b51..6bed78b 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -15,7 +15,7 @@ concurrency:
 jobs:
   linters:
     timeout-minutes: 5
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - name: Checkout 🛎️
         uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
@@ -45,7 +45,7 @@ jobs:
 
   autodoc:
     timeout-minutes: 5
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - name: Checkout
         uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
@@ -69,8 +69,8 @@ jobs:
       fail-fast: false
       matrix:
         os:
-          - ubuntu-24.04        # x86_64-unknown-linux-gnu
-          - ubuntu-24.04-arm    # aarch64-unknown-linux-gnu
+          - ubuntu-26.04        # x86_64-unknown-linux-gnu
+          - ubuntu-26.04-arm    # aarch64-unknown-linux-gnu
           - macos-15-intel      # x86_64-apple-darwin
           - macos-15            # aarch64-apple-darwin
     runs-on: ${{ matrix.os }}
@@ -122,7 +122,7 @@ jobs:
       - linters
       - autodoc
       - test-install
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-26.04
     steps:
       - name: Verify all jobs succeeded
         uses: re-actors/alls-green@05ac9388f0aebcb5727afa17fcccfecd6f8ec5fe # release/v1