diff --git a/pmd-cs/pom.xml b/pmd-cs/pom.xml
index 71710138f3..35e9ba91c2 100644
--- a/pmd-cs/pom.xml
+++ b/pmd-cs/pom.xml
@@ -17,6 +17,28 @@
                 <groupId>org.antlr</groupId>
                 <artifactId>antlr4-maven-plugin</artifactId>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-antrun-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>antlr-cleanup</id>
+                        <phase>generate-sources</phase>
+                        <goals>
+                            <goal>run</goal>
+                        </goals>
+                        <configuration>
+                            <target>
+                                <ant antfile="${antlr4.ant.wrapper}" target="cpd-language">
+                                    <property name="lang-name" value="CSharp" />
+                                    <property name="lang-terse-name" value="cs" />
+                                </ant>
+                            </target>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+
 
             <plugin>
                 <artifactId>maven-resources-plugin</artifactId>
diff --git a/pmd-cs/src/main/antlr4/net/sourceforge/pmd/lang/cs/antlr4/CSharpLexer.g4 b/pmd-cs/src/main/antlr4/net/sourceforge/pmd/lang/cs/ast/CSharpLexer.g4
similarity index 100%
rename from pmd-cs/src/main/antlr4/net/sourceforge/pmd/lang/cs/antlr4/CSharpLexer.g4
rename to pmd-cs/src/main/antlr4/net/sourceforge/pmd/lang/cs/ast/CSharpLexer.g4
diff --git a/pmd-cs/src/main/java/net/sourceforge/pmd/cpd/CsTokenizer.java b/pmd-cs/src/main/java/net/sourceforge/pmd/cpd/CsTokenizer.java
index f355d73502..ad86733beb 100644
--- a/pmd-cs/src/main/java/net/sourceforge/pmd/cpd/CsTokenizer.java
+++ b/pmd-cs/src/main/java/net/sourceforge/pmd/cpd/CsTokenizer.java
@@ -12,7 +12,7 @@ import net.sourceforge.pmd.cpd.internal.AntlrTokenizer;
 import net.sourceforge.pmd.cpd.token.AntlrTokenFilter;
 import net.sourceforge.pmd.lang.ast.impl.antlr4.AntlrToken;
 import net.sourceforge.pmd.lang.ast.impl.antlr4.AntlrTokenManager;
-import net.sourceforge.pmd.lang.cs.antlr4.CSharpLexer;
+import net.sourceforge.pmd.lang.cs.ast.CSharpLexer;
 
 /**
  * The C# tokenizer.