diff --git a/pom.xml b/pom.xml
index e9139da1..0de77b35 100644
--- a/pom.xml
+++ b/pom.xml
@@ -80,7 +80,7 @@
     <maven.surefire.plugin.version>3.5.6</maven.surefire.plugin.version>
     <jetty.server.version>9.4.50.v20221201</jetty.server.version>
     <saxon.version>9.1.0.8</saxon.version>
-    <spotless.version>3.6.0</spotless.version>
+    <spotless.version>3.9.0</spotless.version>
     <!-- Eclipse Java formatter version 4.26+ does not check test files -->
     <spotless.eclipse.version>4.25</spotless.eclipse.version>
     <spotless.eclipse.wtp.version>4.21.0</spotless.eclipse.wtp.version>