diff --git a/.gitignore b/.gitignore
index 0363e0707..a33f0014e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -24,3 +24,4 @@ test-output
 # Misc.
 .DS_Store
 checkstyle.cache
+.flattened-pom.xml
diff --git a/parent/pom.xml b/parent/pom.xml
index 5da1dfcbc..3e78dcfb8 100644
--- a/parent/pom.xml
+++ b/parent/pom.xml
@@ -578,6 +578,11 @@
                         </parameter>
                     </configuration>
                 </plugin>
+                <plugin>
+                    <groupId>org.codehaus.mojo</groupId>
+                    <artifactId>flatten-maven-plugin</artifactId>
+                    <version>1.2.2</version>
+                </plugin>
 
             </plugins>
         </pluginManagement>
@@ -614,6 +619,7 @@
                         <exclude>mvnw*</exclude>
                         <exclude>**/*.asciidoc</exclude>
                         <exclude>**/binding.xjb</exclude>
+                        <exclude>**/*.flattened-pom.xml</exclude>
                     </excludes>
                     <mapping>
                         <java>SLASHSTAR_STYLE</java>
@@ -702,6 +708,34 @@
                     </execution>
                 </executions>
             </plugin>
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>flatten-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <!-- Tidy up all POMs before they are published -->
+                        <id>flatten</id>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>flatten</goal>
+                        </goals>
+                        <configuration>
+                            <updatePomFile>true</updatePomFile>
+                            <flattenMode>ossrh</flattenMode>
+                            <pomElements>
+                                <parent>expand</parent>
+                            </pomElements>
+                        </configuration>
+                    </execution>
+                    <execution>
+                        <id>flatten-clean</id>
+                        <phase>clean</phase>
+                        <goals>
+                            <goal>clean</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>
 
diff --git a/processor/pom.xml b/processor/pom.xml
index dfe9bdbe6..c04730126 100644
--- a/processor/pom.xml
+++ b/processor/pom.xml
@@ -209,6 +209,21 @@
                     </execution>
                 </executions>
             </plugin>
+            <!-- The flatten plugin should run after the shading is done -->
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>flatten-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <!-- Tidy up all POMs before they are published -->
+                        <id>flatten</id>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>flatten</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-dependency-plugin</artifactId>
@@ -334,6 +349,7 @@
                     <artifactId>jaxb-api</artifactId>
                     <version>2.3.1</version>
                     <scope>provided</scope>
+                    <optional>true</optional>
                 </dependency>
             </dependencies>
         </profile>