diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9495ae490f..dc6e8e4c36 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -21,7 +21,7 @@ defaults:
     shell: bash
 
 env:
-  java_version: 17
+  java_version: 21
   java_distribution: zulu
   javadoc_version: 24 # newer than `java_version` for better javadoc
   groovy_version: 4.x
diff --git a/pom.xml b/pom.xml
index dfd02b761f..2546e9a762 100644
--- a/pom.xml
+++ b/pom.xml
@@ -277,7 +277,7 @@
         <artifactId>maven-compiler-plugin</artifactId>
         <version>3.14.1</version>
         <configuration>
-          <release>17</release>
+          <release>21</release>
           <encoding>UTF-8</encoding>
         </configuration>
       </plugin>