diff --git a/src/main/java/org/apache/maven/plugin/compiler/AbstractCompilerMojo.java b/src/main/java/org/apache/maven/plugin/compiler/AbstractCompilerMojo.java
index ea172abd..702a75f0 100644
--- a/src/main/java/org/apache/maven/plugin/compiler/AbstractCompilerMojo.java
+++ b/src/main/java/org/apache/maven/plugin/compiler/AbstractCompilerMojo.java
@@ -30,6 +30,7 @@
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Date;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -472,7 +473,7 @@ public abstract class AbstractCompilerMojo
 
     /**
      * file extensions to check timestamp for incremental build
-     * <b>default contains only <code>.class</code></b>
+     * <b>default contains only <code>class</code></b>
      *
      * @since 3.1
      */
@@ -1566,8 +1567,7 @@ protected boolean isDependencyChanged()
 
         if ( fileExtensions == null || fileExtensions.isEmpty() )
         {
-            fileExtensions = new ArrayList<>();
-            fileExtensions.add( "class" );
+            fileExtensions = Collections.singletonList( "class" );
         }
 
         Date buildStartTime = getBuildStartTime();