diff --git a/.circleci/config.yml b/.circleci/config.yml
index 6e107e00..1dabee7b 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -13,6 +13,10 @@ executors:
     docker:
       - image: circleci/openjdk:17-buster
     resource_class: small
+  scala_jdk21_executor:
+    docker:
+      - image: cimg/openjdk:21.0-node
+    resource_class: small
 
 commands:
   sbt_cmd:
@@ -127,6 +131,18 @@ workflows:
           name: jdk17_3.x
           java_version: jdk17
           scala_version: 3.3.4
+      - scala_job:
+          name: jdk21_2.12.x
+          java_version: jdk21
+          scala_version: 2.12.20
+      - scala_job:
+          name: jdk21_2.13.x
+          java_version: jdk21
+          scala_version: 2.13.15
+      - scala_job:
+          name: jdk21_3.x
+          java_version: jdk21
+          scala_version: 3.3.4
       - scalajs_job:
           name: sjs1.0_2.12.x
           scala_version: 2.12.20
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index dbaf4868..a6000d24 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        java: [8, 11, 17]
+        java: [8, 11, 17, 21]
         scala: [2.12.x, 2.13.x, 3.x]
     runs-on: ubuntu-latest
     steps: