diff --git a/.github/workflows/maven.yml b/.github/workflows/maven.yml
index 5cf42ab..eb427a4 100644
--- a/.github/workflows/maven.yml
+++ b/.github/workflows/maven.yml
@@ -11,7 +11,7 @@ jobs:
     strategy:
       matrix:
         # test against latest update of each major Java version:
-        java: [ 8, 11, 17 ]
+        java: [ 8, 11, 17, 21 ]
     name: Java ${{ matrix.java }}
     steps:
       - uses: actions/checkout@v3
diff --git a/pom.xml b/pom.xml
index 4bdd09b..47ad85e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -18,11 +18,11 @@
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <cdk.version>2.10-SNAPSHOT</cdk.version>
     <depict.version>${project.parent.version}</depict.version>
-    <junit.version>5.10.0</junit.version>
+    <junit.version>5.10.1</junit.version>
     <hamcrest.version>2.2</hamcrest.version>
     <!-- Note -Pjakarta for Spring 6 (Requires Java 17 and JakartaEE) -->
-    <spring-webmvc.version>5.3.29</spring-webmvc.version>
-    <spring-boot.version>2.7.14</spring-boot.version>
+    <spring-webmvc.version>5.3.31</spring-webmvc.version>
+    <spring-boot.version>2.7.18</spring-boot.version>
   </properties>
   <developers>
     <developer>