Allow Maven PMD plugin to override PMD implementation jars with property
"commons.pmd-impl.version".
diff --git a/pom.xml b/pom.xml
index fced5ce..7505af3 100644
--- a/pom.xml
+++ b/pom.xml
@@ -139,6 +139,7 @@
     <commons.jdepend.version>2.0</commons.jdepend.version>
     <commons.jxr.version>3.1.1</commons.jxr.version>
     <commons.pmd.version>3.14.0</commons.pmd.version>
+    <commons.pmd-impl.version>6.29.0</commons.pmd-impl.version>
     <commons.project-info.version>3.1.2</commons.project-info.version>
     <commons.rat.version>0.13</commons.rat.version>
     <commons.release-plugin.version>1.7</commons.release-plugin.version>
@@ -763,6 +764,33 @@
             </dependency>
           </dependencies>
         </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-pmd-plugin</artifactId>
+          <version>${commons.pmd.version}</version>
+          <dependencies>
+            <dependency>
+              <groupId>net.sourceforge.pmd</groupId>
+              <artifactId>pmd-core</artifactId>
+              <version>${commons.pmd-impl.version}</version>
+            </dependency>
+            <dependency>
+              <groupId>net.sourceforge.pmd</groupId>
+              <artifactId>pmd-java</artifactId>
+              <version>${commons.pmd-impl.version}</version>
+            </dependency>
+            <dependency>
+              <groupId>net.sourceforge.pmd</groupId>
+              <artifactId>pmd-javascript</artifactId>
+              <version>${commons.pmd-impl.version}</version>
+            </dependency>
+            <dependency>
+              <groupId>net.sourceforge.pmd</groupId>
+              <artifactId>pmd-jsp</artifactId>
+              <version>${commons.pmd-impl.version}</version>
+            </dependency>
+          </dependencies>
+        </plugin>
       </plugins>
     </pluginManagement>
     <plugins>
diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index 8f08fa1..a964267 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -69,6 +69,7 @@
           <action type="add" dev="sebb">Add .asf.yaml to RAT excludes.</action>
           <action type="add" dev="ggregory">Add versions-maven-plugin run for this build.</action>
           <action type="add" dev="ggregory">Add maven-checkstyle-plugin to pluginManagement.</action>
+          <action type="add" dev="ggregory">Allow Maven PMD plugin to override PMD implementation jars with property "commons.pmd-impl.version".</action>
           <!-- UPDATES -->
           <action type="update" dev="ggregory">Update versions-maven-plugin 2.7 -> 2.8.1.</action>
           <action type="update" dev="ggregory" due-to="Dependabot">Update maven-project-info-reports-plugin from 3.1.0 to 3.1.2 #19, #41.</action>