diff --git a/net.sf.eclipsecs.checkstyle/.classpath b/net.sf.eclipsecs.checkstyle/.classpath
index a23128422..5ed57c8cc 100644
--- a/net.sf.eclipsecs.checkstyle/.classpath
+++ b/net.sf.eclipsecs.checkstyle/.classpath
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <classpath>
-	<classpathentry exported="true" kind="lib" path="checkstyle-10.21.0-all.jar" sourcepath="checkstyle-checkstyle-10.21.0.zip"/>
+	<classpathentry exported="true" kind="lib" path="checkstyle-10.21.1-all.jar" sourcepath="checkstyle-checkstyle-10.21.1.zip"/>
 	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-17">
 		<attributes>
 			<attribute name="maven.pomderived" value="true"/>
diff --git a/net.sf.eclipsecs.checkstyle/META-INF/MANIFEST.MF b/net.sf.eclipsecs.checkstyle/META-INF/MANIFEST.MF
index 0cc3dd2e7..cf64b6b95 100644
--- a/net.sf.eclipsecs.checkstyle/META-INF/MANIFEST.MF
+++ b/net.sf.eclipsecs.checkstyle/META-INF/MANIFEST.MF
@@ -33,5 +33,5 @@ Export-Package: .,
  com.puppycrawl.tools.checkstyle.filters,
  com.puppycrawl.tools.checkstyle.utils
 Bundle-ClassPath: .,
- checkstyle-10.21.0-all.jar
+ checkstyle-10.21.1-all.jar
 Automatic-Module-Name: net.sf.eclipsecs.checkstyle
diff --git a/net.sf.eclipsecs.checkstyle/build.properties b/net.sf.eclipsecs.checkstyle/build.properties
index 4269fc0b1..8490437b1 100644
--- a/net.sf.eclipsecs.checkstyle/build.properties
+++ b/net.sf.eclipsecs.checkstyle/build.properties
@@ -1,7 +1,7 @@
 bin.includes = META-INF/,\
                .,\
                license/,\
-               checkstyle-10.21.0-all.jar,\
+               checkstyle-10.21.1-all.jar,\
                OSGI-INF/
 jars.compile.order = .
 source.. = metadata/
diff --git a/net.sf.eclipsecs.checkstyle/checkstyle-10.21.0-all.jar b/net.sf.eclipsecs.checkstyle/checkstyle-10.21.1-all.jar
similarity index 90%
rename from net.sf.eclipsecs.checkstyle/checkstyle-10.21.0-all.jar
rename to net.sf.eclipsecs.checkstyle/checkstyle-10.21.1-all.jar
index 9b17b500f..9d9c22953 100644
Binary files a/net.sf.eclipsecs.checkstyle/checkstyle-10.21.0-all.jar and b/net.sf.eclipsecs.checkstyle/checkstyle-10.21.1-all.jar differ
diff --git a/net.sf.eclipsecs.checkstyle/pom.xml b/net.sf.eclipsecs.checkstyle/pom.xml
index b1e85393c..dacc797e0 100644
--- a/net.sf.eclipsecs.checkstyle/pom.xml
+++ b/net.sf.eclipsecs.checkstyle/pom.xml
@@ -11,7 +11,7 @@
     <name>Checkstyle Core Library Plugin</name>
 
     <properties>
-        <checkstyle.version>10.21.0</checkstyle.version>
+        <checkstyle.version>10.21.1</checkstyle.version>
     </properties>
     <build>
         <plugins>
diff --git a/net.sf.eclipsecs.core/.classpath b/net.sf.eclipsecs.core/.classpath
index 051313a75..78750f254 100644
--- a/net.sf.eclipsecs.core/.classpath
+++ b/net.sf.eclipsecs.core/.classpath
@@ -7,6 +7,6 @@
 	</classpathentry>
 	<classpathentry kind="con" path="org.eclipse.pde.core.requiredPlugins"/>
 	<classpathentry kind="src" path="src"/>
-	<classpathentry kind="lib" path="lib/checkstyle-10.21.0-all.jar"/>
+	<classpathentry kind="lib" path="lib/checkstyle-10.21.1-all.jar"/>
 	<classpathentry kind="output" path="target/classes"/>
 </classpath>
diff --git a/net.sf.eclipsecs.core/META-INF/MANIFEST.MF b/net.sf.eclipsecs.core/META-INF/MANIFEST.MF
index 9f7b17f35..69cef6714 100644
--- a/net.sf.eclipsecs.core/META-INF/MANIFEST.MF
+++ b/net.sf.eclipsecs.core/META-INF/MANIFEST.MF
@@ -5,7 +5,7 @@ Bundle-SymbolicName: net.sf.eclipsecs.core;singleton:=true
 Bundle-Version: 10.21.0.qualifier
 Bundle-RequiredExecutionEnvironment: JavaSE-17
 Bundle-ClassPath: .,
- lib/checkstyle-10.21.0-all.jar
+ lib/checkstyle-10.21.1-all.jar
 Bundle-Activator: net.sf.eclipsecs.core.CheckstylePlugin
 Bundle-ActivationPolicy: lazy
 Bundle-Vendor: %Bundle-Vendor
diff --git a/net.sf.eclipsecs.core/build.properties b/net.sf.eclipsecs.core/build.properties
index 3ed46dc62..2b621f47e 100644
--- a/net.sf.eclipsecs.core/build.properties
+++ b/net.sf.eclipsecs.core/build.properties
@@ -6,6 +6,6 @@ bin.includes = .,\
                license/,\
                plugin.xml,\
                schema/,\
-               lib/checkstyle-10.21.0-all.jar,\
+               lib/checkstyle-10.21.1-all.jar,\
                OSGI-INF/
 javacDefaultEncoding.. = UTF-8
diff --git a/net.sf.eclipsecs.core/lib/checkstyle-10.21.0-all.jar b/net.sf.eclipsecs.core/lib/checkstyle-10.21.1-all.jar
similarity index 90%
rename from net.sf.eclipsecs.core/lib/checkstyle-10.21.0-all.jar
rename to net.sf.eclipsecs.core/lib/checkstyle-10.21.1-all.jar
index 9b17b500f..9d9c22953 100644
Binary files a/net.sf.eclipsecs.core/lib/checkstyle-10.21.0-all.jar and b/net.sf.eclipsecs.core/lib/checkstyle-10.21.1-all.jar differ
diff --git a/upgrade-version.build.xml b/upgrade-version.build.xml
index b30205c4a..c65eca2e7 100644
--- a/upgrade-version.build.xml
+++ b/upgrade-version.build.xml
@@ -18,8 +18,8 @@ Apply all necessary manual code changes now.
 	<description>upgrade all version numbers</description>
 
 	<target name="upgrade-version" description="upgrade version numbers and dependent files">
-		<property name="fromVersion" value="10.20.2"/>
-		<property name="toVersion" value="10.21.0"/>
+		<property name="fromVersion" value="10.21.0"/>
+		<property name="toVersion" value="10.21.1"/>
 
 		<!-- delete all outdated files, independent of their current version -->
 		<delete>