diff --git a/src/it/MPMD-290-cpd-for-csharp/invoker.properties b/src/it/MPMD-290-cpd-for-csharp/invoker.properties
new file mode 100644
index 0000000..7154df4
--- /dev/null
+++ b/src/it/MPMD-290-cpd-for-csharp/invoker.properties
@@ -0,0 +1,20 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+invoker.goals = clean verify
+invoker.buildResult = failure
+invoker.debug = true
diff --git a/src/it/MPMD-290-cpd-for-csharp/pom.xml b/src/it/MPMD-290-cpd-for-csharp/pom.xml
new file mode 100644
index 0000000..38907b4
--- /dev/null
+++ b/src/it/MPMD-290-cpd-for-csharp/pom.xml
@@ -0,0 +1,68 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>org.apache.maven.plugins.pmd.its</groupId>
+  <artifactId>MPMD-290-cpd-for-csharp</artifactId>
+  <version>1.0-SNAPSHOT</version>
+
+  <description>
+    Use CPD via m-pmd-p to analyze duplications in c# files.
+  </description>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-pmd-plugin</artifactId>
+        <version>@project.version@</version>
+        <configuration>
+          <language>cs</language>
+          <minimumTokens>10</minimumTokens>
+          <includes>
+            <include>**/*.cs</include>
+          </includes>
+          <compileSourceRoots>
+            <compileSourceRoot>${basedir}/src/main/cs</compileSourceRoot>
+          </compileSourceRoots>
+          <printFailingErrors>true</printFailingErrors>
+        </configuration>
+        <executions>
+          <execution>
+            <goals>
+              <goal>cpd-check</goal>
+            </goals>
+          </execution>
+        </executions>
+        <dependencies>
+            <dependency>
+                <groupId>net.sourceforge.pmd</groupId>
+                <artifactId>pmd-cs</artifactId>
+                <version>@pmdVersion@</version>
+            </dependency>
+        </dependencies>
+      </plugin>
+    </plugins>
+  </build>
+
+</project>
diff --git a/src/it/MPMD-290-cpd-for-csharp/src/main/cs/Sample1.cs b/src/it/MPMD-290-cpd-for-csharp/src/main/cs/Sample1.cs
new file mode 100644
index 0000000..de5f199
--- /dev/null
+++ b/src/it/MPMD-290-cpd-for-csharp/src/main/cs/Sample1.cs
@@ -0,0 +1,26 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+class Sample1 {
+    public void bar() {
+        int x = 1;
+        int y = 2;
+        int z = x + y;
+    }
+}
\ No newline at end of file
diff --git a/src/it/MPMD-290-cpd-for-csharp/src/main/cs/Sample2.cs b/src/it/MPMD-290-cpd-for-csharp/src/main/cs/Sample2.cs
new file mode 100644
index 0000000..8730046
--- /dev/null
+++ b/src/it/MPMD-290-cpd-for-csharp/src/main/cs/Sample2.cs
@@ -0,0 +1,26 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+class Sample2 {
+    public void bar() {
+        int x = 1;
+        int y = 2;
+        int z = x + y;
+    }
+}
\ No newline at end of file
diff --git a/src/it/MPMD-290-cpd-for-csharp/verify.groovy b/src/it/MPMD-290-cpd-for-csharp/verify.groovy
new file mode 100644
index 0000000..18b724a
--- /dev/null
+++ b/src/it/MPMD-290-cpd-for-csharp/verify.groovy
@@ -0,0 +1,36 @@
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+File buildLog = new File( basedir, 'build.log' )
+assert buildLog.exists()
+
+assert buildLog.text.contains( "[INFO] CPD Failure: Found 7 lines of duplicated code at locations" )
+assert buildLog.text.contains( "[DEBUG] PMD failureCount: 1, warningCount: 0" )
+
+File cpdXml = new File( basedir, 'target/cpd.xml' )
+assert cpdXml.exists()
+
+// no duplication for the license header - if this is reported, then CPD uses the wrong language/tokenizer
+assert !cpdXml.text.contains( '<duplication lines="20" tokens="148">' )
+assert !cpdXml.text.contains( 'line="1"' )
+
+// the only valid duplication
+assert cpdXml.text.contains( '<duplication lines="7" tokens="26">' )
+assert cpdXml.text.contains( 'line="20"' )
diff --git a/src/site/apt/examples/cpdCsharp.apt.vm b/src/site/apt/examples/cpdCsharp.apt.vm
new file mode 100644
index 0000000..4fbf230
--- /dev/null
+++ b/src/site/apt/examples/cpdCsharp.apt.vm
@@ -0,0 +1,91 @@
+ ------
+ Finding duplicated code in C#
+ ------
+ Andreas Dangel
+ ------
+ 2020-10-02
+ ------
+
+ ~~ Licensed to the Apache Software Foundation (ASF) under one
+ ~~ or more contributor license agreements.  See the NOTICE file
+ ~~ distributed with this work for additional information
+ ~~ regarding copyright ownership.  The ASF licenses this file
+ ~~ to you under the Apache License, Version 2.0 (the
+ ~~ "License"); you may not use this file except in compliance
+ ~~ with the License.  You may obtain a copy of the License at
+ ~~
+ ~~   http://www.apache.org/licenses/LICENSE-2.0
+ ~~
+ ~~ Unless required by applicable law or agreed to in writing,
+ ~~ software distributed under the License is distributed on an
+ ~~ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ ~~ KIND, either express or implied.  See the License for the
+ ~~ specific language governing permissions and limitations
+ ~~ under the License.
+
+~~ NOTE: For help with the syntax of this file, see:
+~~ http://maven.apache.org/doxia/references/apt-format.html
+
+Finding duplicated code in C#
+
+ By default, the maven-pmd-plugin only supports the languages Java, JavaScript and JSP.
+ But {{{https://pmd.github.io/latest/pmd_userdocs_cpd.html#supported-languages}CPD supports many more languages}},
+ e.g. C#. In order to enable C# in your build, you need to
+ configure several parts:
+ 
+ * Add an additional plugin dependency for c# (pmd-cs module)
+
+ * Select the language <<<cs>>>.
+
+ * Configure the includes filter to consider <<<*.cs>>> (otherwise only java files will be analyzed)
+
+ * Configure the source directory (by default, only <<<src/main/java>>> is analyzed)
+
+
++-----+
+<project>
+  ...
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-pmd-plugin</artifactId>
+        <version>${project.version}</version>
+        <configuration>
+          <language>cs</language>
+          <minimumTokens>10</minimumTokens>
+          <includes>
+            <include>**/*.cs</include>
+          </includes>
+          <compileSourceRoots>
+            <compileSourceRoot>${basedir}/src/main/cs</compileSourceRoot>
+          </compileSourceRoots>
+          <printFailingErrors>true</printFailingErrors>
+        </configuration>
+        <executions>
+          <execution>
+            <goals>
+              <goal>cpd-check</goal>
+            </goals>
+          </execution>
+        </executions>
+        <dependencies>
+            <dependency>
+                <groupId>net.sourceforge.pmd</groupId>
+                <artifactId>pmd-cs</artifactId>
+                <version>${pmdVersion}</version>
+            </dependency>
+        </dependencies>
+      </plugin>
+      ...
+    </plugins>
+  </build>
+</project>
++-----+
+
+ In this example, the C# source files are located in <<<src/main/cs>>>.
+
+ <<Note:>> The version for <<<net.sourceforge.pmd:pmd-cs>>> needs to match the PMD version, that is
+ being used. If you {{{./upgrading-PMD-at-runtime.html}upgrade PMD at runtime}} you'll need to make
+ sure, to change the version here as well.
+
diff --git a/src/site/apt/index.apt.vm b/src/site/apt/index.apt.vm
index 38161a7..ff3bceb 100644
--- a/src/site/apt/index.apt.vm
+++ b/src/site/apt/index.apt.vm
@@ -98,4 +98,6 @@
 
   * {{{./examples/jspReport.html}Analyzing Java Server Pages Code}}
 
+  * {{{./examples/cpdCsharp.html}Finding duplicated code in C#}}
+
   []
diff --git a/src/site/site.xml b/src/site/site.xml
index ca64ccb..455f516 100644
--- a/src/site/site.xml
+++ b/src/site/site.xml
@@ -42,6 +42,7 @@
       <item name="Analyzing JavaScript" href="examples/javascriptReport.html"/>
       <item name="Analyzing Java Server Pages" href="examples/jspReport.html"/>
       <item name="Violations Exclusions" href="examples/violation-exclusions.html"/>
+      <item name="Duplicated code in C#" href="examples/cpdCsharp.html"/>
     </menu>
   </body>
 </project>