diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index 663406e9e..0b69cc3d0 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -14,7 +14,7 @@ jobs:
       fail-fast: false
       matrix:
         SCALA_VERSION: [2.12, 2.13, 3]
-        JDK: [8, 11, 17, 20]
+        JDK: [8, 11, 17, 21]
         PEKKO_VERSION: [default, main]
     steps:
       - name: Checkout