diff --git a/pom.xml b/pom.xml
index 595d7b5..a29f8f2 100644
--- a/pom.xml
+++ b/pom.xml
@@ -273,7 +273,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-jxr-plugin</artifactId>
-        <version>3.3.0</version>
+        <version>3.3.1</version>
         <configuration>
           <aggregate>true</aggregate>
           <linkJavadoc>true</linkJavadoc>
@@ -287,7 +287,7 @@
       <plugin>
         <artifactId>maven-pmd-plugin</artifactId>
         <!-- Later versions require Java 1.6+ -->
-        <version>3.20.0</version>
+        <version>3.21.2</version>
         <configuration>
           <linkXRef>true</linkXRef>
           <sourceEncoding>utf-8</sourceEncoding>
@@ -354,7 +354,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-project-info-reports-plugin</artifactId>
-        <version>3.4.3</version>
+        <version>3.5.0</version>
       </plugin>
       <plugin>
         <groupId>org.apache.rat</groupId>