diff --git a/src/main/resources/io/netty/checkstyle.xml b/src/main/resources/io/netty/checkstyle.xml
index 2f8beb8..574e345 100644
--- a/src/main/resources/io/netty/checkstyle.xml
+++ b/src/main/resources/io/netty/checkstyle.xml
@@ -9,6 +9,11 @@
   <module name="FileTabCharacter"/>
   <module name="JavadocPackage"/>
   <module name="NewlineAtEndOfFile"/>
+  <module name="RegexpSingleline">
+    <property name="format" value="^(\s|\*)*Copyright\s+[0-9]+\s+The Netty Project\s*$"/>
+    <property name="minimum" value="1"/>
+    <property name="maximum" value="1"/>
+  </module>
   <module name="RegexpSingleline">
     <property name="format" value="(@(author|version)|\(non-Javadoc\))"/>
     <property name="ignoreCase" value="true"/>