diff --git a/checkstyle.xml b/checkstyle.xml
index aedcb2e..d3e35d0 100644
--- a/checkstyle.xml
+++ b/checkstyle.xml
@@ -24,6 +24,9 @@
 <module name="Checker">
   <property name="localeLanguage" value="en"/>
   <module name="JavadocPackage"/>
+  <module name="LineLength">
+    <property name="max" value="120"/>
+  </module>
   <module name="NewlineAtEndOfFile">
     <property name="lineSeparator" value="lf" />
   </module>
diff --git a/ftplet-api/src/main/java/org/apache/ftpserver/ftplet/DataTransferFtpReply.java b/ftplet-api/src/main/java/org/apache/ftpserver/ftplet/DataTransferFtpReply.java
index f486a99..3812733 100644
--- a/ftplet-api/src/main/java/org/apache/ftpserver/ftplet/DataTransferFtpReply.java
+++ b/ftplet-api/src/main/java/org/apache/ftpserver/ftplet/DataTransferFtpReply.java
@@ -23,15 +23,15 @@
  * A more specific type of FTP reply that is sent by the commands that transfer
  * data over the data connection. These commands include LIST, RETR, STOR, STOU
  * etc.
- * 
+ *
  * @author <a href="http://mina.apache.org">Apache MINA Project</a>
- * 
+ *
  */
 
 public interface DataTransferFtpReply extends FileActionFtpReply {
     /**
      * Returns the number of bytes transferred.
-     * 
+     *
      * @return the number of bytes transferred.
      */
     long getBytesTransferred();
diff --git a/ftplet-api/src/main/java/org/apache/ftpserver/ftplet/Ftplet.java b/ftplet-api/src/main/java/org/apache/ftpserver/ftplet/Ftplet.java
index 605ae38..b503b97 100644
--- a/ftplet-api/src/main/java/org/apache/ftpserver/ftplet/Ftplet.java
+++ b/ftplet-api/src/main/java/org/apache/ftpserver/ftplet/Ftplet.java
@@ -23,14 +23,14 @@
 
 /**
  * Defines methods that all ftplets must implement.
- * 
+ *
  * A ftplet is a small Java program that runs within an FTP server. Ftplets
  * receive and respond to requests from FTP clients.
- * 
+ *
  * This interface defines methods to initialize a ftplet, to service requests,
  * and to remove a ftplet from the server. These are known as life-cycle methods
  * and are called in the following sequence:
- * 
+ *
  * <ol>
  * <li>The ftplet is constructed.</li>
  * <li>Then initialized with the init method.</li>
@@ -39,7 +39,7 @@
  * method.</li>
  * <li>Then garbage collected and finalized.</li>
  * </ol>
- * 
+ *
  * All the callback methods return FtpletEnum. If it returns null
  * FtpletEnum.DEFAULT will be assumed. If any ftplet callback method throws
  * exception, that particular connection will be disconnected.
@@ -54,7 +54,7 @@
      * exactly once after instantiating the ftplet. The init method must
      * complete successfully before the ftplet can receive any requests.
      * @param ftpletContext The current {@link FtpletContext}
-     * @throws FtpException 
+     * @throws FtpException
      */
     void init(FtpletContext ftpletContext) throws FtpException;
 
@@ -84,7 +84,7 @@
      * disconnect the client.</li>
      * <li>Ftplet throws exception: Same as {@link FtpletResult#DISCONNECT}</li>
      * </ul>
-     * 
+     *
      * @param session
      *            The current session
      * @param request
@@ -109,7 +109,7 @@
      * disconnect the client.</li>
      * <li>Ftplet throws exception: Same as {@link FtpletResult#DISCONNECT}</li>
      * </ul>
-     * 
+     *
      * @param session
      *            The current session
      * @param request
@@ -129,8 +129,8 @@
      * Client connect notification method.
      * @param session The current {@link FtpSession}
      * @return The desired action to be performed by the server
-     * @throws FtpException 
-     * @throws IOException 
+     * @throws FtpException
+     * @throws IOException
      */
     FtpletResult onConnect(FtpSession session) throws FtpException, IOException;
 
@@ -138,8 +138,8 @@
      * Client disconnect notification method. This is the last callback method.
      * @param session The current {@link FtpSession}
      * @return The desired action to be performed by the server
-     * @throws FtpException 
-     * @throws IOException 
+     * @throws FtpException
+     * @throws IOException
      */
     FtpletResult onDisconnect(FtpSession session) throws FtpException,
             IOException;
diff --git a/pom.xml b/pom.xml
index e7bd401..8f492eb 100644
--- a/pom.xml
+++ b/pom.xml
@@ -174,7 +174,7 @@
     <slf4j.log4j12.version>1.7.32</slf4j.log4j12.version>
     <spring.context.version>2.5.5</spring.context.version>
     <checkstyle.plugin.version>3.1.2</checkstyle.plugin.version>
-    <checkstyle.version>8.45.1</checkstyle.version>
+    <checkstyle.version>9.2.1</checkstyle.version>
     <checkstyle.configdir>${basedir}</checkstyle.configdir>
   </properties>
 
@@ -334,6 +334,19 @@
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-javadoc-plugin</artifactId>
         </plugin>
+
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-checkstyle-plugin</artifactId>
+          <version>${checkstyle.plugin.version}</version>
+          <dependencies>
+            <dependency>
+              <groupId>com.puppycrawl.tools</groupId>
+              <artifactId>checkstyle</artifactId>
+              <version>${checkstyle.version}</version>
+            </dependency>
+          </dependencies>
+        </plugin>
       </plugins>
     </pluginManagement>
 
@@ -526,7 +539,7 @@
               <dependency>
                 <groupId>com.puppycrawl.tools</groupId>
                 <artifactId>checkstyle</artifactId>
-                <version>9.2</version>
+                <version>${checksytyle.version}</version>
               </dependency>
             </dependencies>
             <executions>