diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/gui/Main.java b/src/main/java/com/puppycrawl/tools/checkstyle/gui/Main.java
index af1eb07c2..8dfd37a98 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/gui/Main.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/gui/Main.java
@@ -30,7 +30,7 @@ import com.puppycrawl.tools.checkstyle.api.DetailAST;
 /**
  * Entry point for starting the checkstyle GUI.
  */
-public class Main {
+public final class Main {
     /**
      * Main frame
      */