diff --git a/antlr4-wrapper.xml b/antlr4-wrapper.xml
index 4036aa009a..b17002f40a 100644
--- a/antlr4-wrapper.xml
+++ b/antlr4-wrapper.xml
@@ -12,7 +12,14 @@
 
         See AntlrGeneratedParserBase
 
+        It also uses the following maven properties:
+         - ant.contrib.jar:  Location of the ant-contrib jar
 -->
+    <taskdef resource="net/sf/antcontrib/antcontrib.properties">
+        <classpath>
+            <pathelement location="${ant.contrib.jar}"/>
+        </classpath>
+    </taskdef>
 
     <property name="target-package-dir" value="${antlr4.outputDirectory}/net/sourceforge/pmd/lang/${lang-id}/ast"/>
     <property name="stamp-file" value="${project.build.directory}/last-generated-timestamp" />
@@ -55,6 +62,75 @@
         <touch file="${stamp-file}" />
     </target>
 
+    <target name="annotate-classes" description="Adds the @Generated annotation to all classes"
+            unless="processing-not-required">
+        <if>
+            <available file="${parser-file}"/>
+            <then>
+                <replace file="${parser-file}"
+                         token="public class ${parser-name}"
+                         value='@net.sourceforge.pmd.annotation.Generated("org.antlr.v4.Tool")${line.separator}
+public class ${parser-name}'/>
+
+                <!-- Parse tree classes for each element -->
+                <replace file="${parser-file}"
+                         token="public static class "
+                         value='@net.sourceforge.pmd.annotation.Generated("org.antlr.v4.Tool")${line.separator}
+public static class '/>
+            </then>
+        </if>
+
+        <if>
+            <available file="${visitor-file}"/>
+            <then>
+                <replace file="${visitor-file}"
+                         token="public interface ${visitor-name}"
+                         value='@net.sourceforge.pmd.annotation.Generated("org.antlr.v4.Tool")${line.separator}
+public interface ${visitor-name}'/>
+            </then>
+        </if>
+
+        <if>
+            <available file="${base-visitor-file}"/>
+            <then>
+                <replace file="${base-visitor-file}"
+                         token="public class ${base-visitor-name}"
+                         value='@net.sourceforge.pmd.annotation.Generated("org.antlr.v4.Tool")${line.separator}
+public class ${base-visitor-name}'/>
+            </then>
+        </if>
+
+        <if>
+            <available file="${listener-file}"/>
+            <then>
+                <replace file="${listener-file}"
+                         token="public interface ${listener-name}"
+                         value='@net.sourceforge.pmd.annotation.Generated("org.antlr.v4.Tool")${line.separator}
+public interface ${listener-name}'/>
+            </then>
+        </if>
+
+        <if>
+            <available file="${base-listener-file}"/>
+            <then>
+                <replace file="${base-listener-file}"
+                         token="public class ${base-listener-name}"
+                         value='@net.sourceforge.pmd.annotation.Generated("org.antlr.v4.Tool")${line.separator}
+public class ${base-listener-name}'/>
+            </then>
+        </if>
+
+        <if>
+            <available file="${lexer-file}"/>
+            <then>
+                <replace file="${lexer-file}"
+                         token="public class ${lexer-name}"
+                         value='@net.sourceforge.pmd.annotation.Generated("org.antlr.v4.Tool")${line.separator}
+public class ${lexer-name}'/>
+            </then>
+        </if>
+    </target>
+
     <condition property="rename-parser">
         <and>
             <not>
@@ -87,7 +163,7 @@
               tofile="${parser-file}"/>
     </target>
 
-    <target name="cpd-language" depends="check-up-to-date, cpd-language-processing, update-stamp-file"/>
+    <target name="cpd-language" depends="check-up-to-date, annotate-classes, cpd-language-processing, update-stamp-file"/>
     <target name="cpd-language-processing" description="Adapt Antlr sources for CPD-only languages"
             unless="processing-not-required">
         <!-- We only need the Lexer file. -->
diff --git a/pmd-cs/pom.xml b/pmd-cs/pom.xml
index 0eec39f809..f4879ed0e7 100644
--- a/pmd-cs/pom.xml
+++ b/pmd-cs/pom.xml
@@ -30,6 +30,7 @@
                         <configuration>
                             <target>
                                 <ant antfile="${antlr4.ant.wrapper}" target="cpd-language">
+                                    <property name="ant.contrib.jar" value="${ant.contrib.jar}" />
                                     <property name="lang-name" value="CSharp" />
                                     <property name="lang-id" value="cs" />
                                 </ant>
diff --git a/pmd-dart/pom.xml b/pmd-dart/pom.xml
index 496115127b..f772795832 100644
--- a/pmd-dart/pom.xml
+++ b/pmd-dart/pom.xml
@@ -30,6 +30,7 @@
                         <configuration>
                             <target>
                                 <ant antfile="${antlr4.ant.wrapper}" target="cpd-language">
+                                    <property name="ant.contrib.jar" value="${ant.contrib.jar}" />
                                     <property name="lang-name" value="Dart" />
                                     <property name="lang-id" value="dart" />
                                 </ant>
diff --git a/pmd-go/pom.xml b/pmd-go/pom.xml
index 4df297ebc9..cf47e5217c 100644
--- a/pmd-go/pom.xml
+++ b/pmd-go/pom.xml
@@ -30,6 +30,7 @@
                         <configuration>
                             <target>
                                 <ant antfile="${antlr4.ant.wrapper}" target="cpd-language">
+                                    <property name="ant.contrib.jar" value="${ant.contrib.jar}" />
                                     <property name="lang-name" value="Golang" />
                                     <property name="lang-id" value="go" />
                                 </ant>
diff --git a/pmd-lua/pom.xml b/pmd-lua/pom.xml
index f3a24be6d3..c8adda151f 100644
--- a/pmd-lua/pom.xml
+++ b/pmd-lua/pom.xml
@@ -30,6 +30,7 @@
                         <configuration>
                             <target>
                                 <ant antfile="${antlr4.ant.wrapper}" target="cpd-language">
+                                    <property name="ant.contrib.jar" value="${ant.contrib.jar}" />
                                     <property name="lang-name" value="Lua" />
                                     <property name="lang-id" value="lua" />
                                 </ant>
diff --git a/pom.xml b/pom.xml
index 8f0474ab59..0f41e68e7d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -122,6 +122,9 @@
         <javacc.outputDirectory>${project.build.directory}/generated-sources/javacc</javacc.outputDirectory>
         <javacc.ant.wrapper>${project.basedir}/../javacc-wrapper.xml</javacc.ant.wrapper>
 
+        <ant-contrib.version>1.0b3</ant-contrib.version>
+        <ant.contrib.jar>${settings.localRepository}/ant-contrib/ant-contrib/${ant-contrib.version}/ant-contrib-${ant-contrib.version}.jar</ant.contrib.jar>
+
         <antlr4.outputDirectory>${project.build.directory}/generated-sources/antlr4</antlr4.outputDirectory>
         <antlr4.ant.wrapper>${project.basedir}/../antlr4-wrapper.xml</antlr4.ant.wrapper>
 
@@ -167,6 +170,11 @@
                             <artifactId>ant</artifactId>
                             <version>${ant.version}</version>
                         </dependency>
+                        <dependency>
+                            <groupId>ant-contrib</groupId>
+                            <artifactId>ant-contrib</artifactId>
+                            <version>${ant-contrib.version}</version>
+                        </dependency>
                     </dependencies>
                 </plugin>
                 <plugin>