diff --git a/src/main/java/org/apache/maven/plugins/javadoc/AggregatorJavadocJarMojo.java b/src/main/java/org/apache/maven/plugins/javadoc/AggregatorJavadocJarMojo.java
index 36acbe862..775cbfda7 100644
--- a/src/main/java/org/apache/maven/plugins/javadoc/AggregatorJavadocJarMojo.java
+++ b/src/main/java/org/apache/maven/plugins/javadoc/AggregatorJavadocJarMojo.java
@@ -47,7 +47,8 @@
         name = "aggregate-jar",
         defaultPhase = LifecyclePhase.PACKAGE,
         aggregator = true,
-        requiresDependencyResolution = ResolutionScope.COMPILE)
+        requiresDependencyResolution = ResolutionScope.COMPILE,
+        threadSafe = true)
 @Execute(phase = LifecyclePhase.COMPILE)
 public class AggregatorJavadocJarMojo extends JavadocJarMojo {
 
diff --git a/src/main/java/org/apache/maven/plugins/javadoc/AggregatorJavadocNoForkReport.java b/src/main/java/org/apache/maven/plugins/javadoc/AggregatorJavadocNoForkReport.java
index f062baa8f..1b3b6fd19 100644
--- a/src/main/java/org/apache/maven/plugins/javadoc/AggregatorJavadocNoForkReport.java
+++ b/src/main/java/org/apache/maven/plugins/javadoc/AggregatorJavadocNoForkReport.java
@@ -38,7 +38,7 @@
  *
  * @since 3.1.0
  */
-@Mojo(name = "aggregate-no-fork", requiresDependencyResolution = ResolutionScope.COMPILE)
+@Mojo(name = "aggregate-no-fork", requiresDependencyResolution = ResolutionScope.COMPILE, threadSafe = true)
 @Execute(phase = LifecyclePhase.NONE)
 public class AggregatorJavadocNoForkReport extends AggregatorJavadocReport {
 
diff --git a/src/main/java/org/apache/maven/plugins/javadoc/AggregatorJavadocReport.java b/src/main/java/org/apache/maven/plugins/javadoc/AggregatorJavadocReport.java
index 4bd99e8d8..8c20e3129 100644
--- a/src/main/java/org/apache/maven/plugins/javadoc/AggregatorJavadocReport.java
+++ b/src/main/java/org/apache/maven/plugins/javadoc/AggregatorJavadocReport.java
@@ -41,7 +41,7 @@
  * @author <a href="mailto:vincent.siveton@gmail.com">Vincent Siveton</a>
  * @since 2.5
  */
-@Mojo(name = "aggregate", aggregator = true, requiresDependencyResolution = ResolutionScope.COMPILE)
+@Mojo(name = "aggregate", aggregator = true, requiresDependencyResolution = ResolutionScope.COMPILE, threadSafe = true)
 @Execute(phase = LifecyclePhase.COMPILE)
 public class AggregatorJavadocReport extends JavadocReport {
 
diff --git a/src/main/java/org/apache/maven/plugins/javadoc/AggregatorTestJavadocJarMojo.java b/src/main/java/org/apache/maven/plugins/javadoc/AggregatorTestJavadocJarMojo.java
index f1a21ce15..f2d432d57 100644
--- a/src/main/java/org/apache/maven/plugins/javadoc/AggregatorTestJavadocJarMojo.java
+++ b/src/main/java/org/apache/maven/plugins/javadoc/AggregatorTestJavadocJarMojo.java
@@ -47,7 +47,8 @@
         name = "test-aggregate-jar",
         defaultPhase = LifecyclePhase.PACKAGE,
         aggregator = true,
-        requiresDependencyResolution = ResolutionScope.TEST)
+        requiresDependencyResolution = ResolutionScope.TEST,
+        threadSafe = true)
 @Execute(phase = LifecyclePhase.TEST_COMPILE)
 public class AggregatorTestJavadocJarMojo extends TestJavadocJarMojo {
 
diff --git a/src/main/java/org/apache/maven/plugins/javadoc/AggregatorTestJavadocNoForkReport.java b/src/main/java/org/apache/maven/plugins/javadoc/AggregatorTestJavadocNoForkReport.java
index 0ac6aca1c..3e646197d 100644
--- a/src/main/java/org/apache/maven/plugins/javadoc/AggregatorTestJavadocNoForkReport.java
+++ b/src/main/java/org/apache/maven/plugins/javadoc/AggregatorTestJavadocNoForkReport.java
@@ -39,7 +39,7 @@
  * @version $Id$
  * @since 3.0.1
  */
-@Mojo(name = "test-aggregate-no-fork", requiresDependencyResolution = ResolutionScope.TEST)
+@Mojo(name = "test-aggregate-no-fork", requiresDependencyResolution = ResolutionScope.TEST, threadSafe = true)
 @Execute(phase = LifecyclePhase.NONE)
 public class AggregatorTestJavadocNoForkReport extends AggregatorTestJavadocReport {
 
diff --git a/src/main/java/org/apache/maven/plugins/javadoc/AggregatorTestJavadocReport.java b/src/main/java/org/apache/maven/plugins/javadoc/AggregatorTestJavadocReport.java
index 06db5a725..fa64b20b8 100644
--- a/src/main/java/org/apache/maven/plugins/javadoc/AggregatorTestJavadocReport.java
+++ b/src/main/java/org/apache/maven/plugins/javadoc/AggregatorTestJavadocReport.java
@@ -41,7 +41,11 @@
  * @author <a href="mailto:vincent.siveton@gmail.com">Vincent Siveton</a>
  * @since 2.5
  */
-@Mojo(name = "test-aggregate", aggregator = true, requiresDependencyResolution = ResolutionScope.TEST)
+@Mojo(
+        name = "test-aggregate",
+        aggregator = true,
+        requiresDependencyResolution = ResolutionScope.TEST,
+        threadSafe = true)
 @Execute(phase = LifecyclePhase.TEST_COMPILE)
 public class AggregatorTestJavadocReport extends TestJavadocReport {