diff --git a/.github/workflows/java-17-baseline.yml b/.github/workflows/java-17-baseline.yml
index e1d081a..e503f62 100644
--- a/.github/workflows/java-17-baseline.yml
+++ b/.github/workflows/java-17-baseline.yml
@@ -2,15 +2,15 @@ name: Java 17 baseline build
 
 on:
   push:
-    branches: [ main ]
+    branches: [ 2.4.x, 2.3.x, 2.2.x, 2.1.x, 2.0.x ]
   pull_request:
-    branches: [ main ]
+    branches: [ 2.4.x, 2.3.x, 2.2.x, 2.1.x, 2.0.x ]
 
 jobs:
   build:
     strategy:
       matrix:
-        java: [ '17' ]
+        java: [ '17', '21' ]
     uses: ./.github/workflows/gradle-build.yml
     with:
       java-version: ${{ matrix.java }}
diff --git a/.github/workflows/java-8-baseline.yml b/.github/workflows/java-8-baseline.yml
index 0ea16bd..a339d4a 100644
--- a/.github/workflows/java-8-baseline.yml
+++ b/.github/workflows/java-8-baseline.yml
@@ -10,7 +10,7 @@ jobs:
   build:
     strategy:
       matrix:
-        java: [ '8', '11', '17' ]
+        java: [ '8', '11', '17', '21' ]
     uses: ./.github/workflows/gradle-build.yml
     with:
       java-version: ${{ matrix.java }}