diff --git a/src/it/MCHECKSTYLE-131/checkstyle.xml b/src/it/MCHECKSTYLE-131/checkstyle.xml
index 5d86167c..81c0c77b 100644
--- a/src/it/MCHECKSTYLE-131/checkstyle.xml
+++ b/src/it/MCHECKSTYLE-131/checkstyle.xml
@@ -17,7 +17,7 @@ KIND, either express or implied.  See the License for the
 specific language governing permissions and limitations
 under the License.
 -->
-<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.2//EN" "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
+<!DOCTYPE module PUBLIC "-//Checkstyle//DTD Checkstyle Configuration 1.2//EN" "https://checkstyle.org/dtds/configuration_1_2.dtd">
 <module name="Checker">
 <module name="JavadocPackage"/>
 </module>
\ No newline at end of file
diff --git a/src/it/MCHECKSTYLE-137/checkstyle.xml b/src/it/MCHECKSTYLE-137/checkstyle.xml
index d4316c3d..29f8b82f 100644
--- a/src/it/MCHECKSTYLE-137/checkstyle.xml
+++ b/src/it/MCHECKSTYLE-137/checkstyle.xml
@@ -17,7 +17,7 @@ KIND, either express or implied.  See the License for the
 specific language governing permissions and limitations
 under the License.
 -->
-<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.2//EN" "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
+<!DOCTYPE module PUBLIC "-//Checkstyle//DTD Checkstyle Configuration 1.2//EN" "https://checkstyle.org/dtds/configuration_1_2.dtd">
 <module name="Checker">
     <module name="TreeWalker">
         <!-- Checks for Naming Conventions.                  -->
diff --git a/src/it/MCHECKSTYLE-169/build-tools/src/main/resources/com/company/build-tools/checkstyle-suppressions.xml b/src/it/MCHECKSTYLE-169/build-tools/src/main/resources/com/company/build-tools/checkstyle-suppressions.xml
index ba46c75b..39da8748 100644
--- a/src/it/MCHECKSTYLE-169/build-tools/src/main/resources/com/company/build-tools/checkstyle-suppressions.xml
+++ b/src/it/MCHECKSTYLE-169/build-tools/src/main/resources/com/company/build-tools/checkstyle-suppressions.xml
@@ -20,8 +20,8 @@ under the License.
 -->
 
 <!DOCTYPE suppressions PUBLIC
-    "-//Puppy Crawl//DTD Suppressions 1.0//EN"
-    "http://www.puppycrawl.com/dtds/suppressions_1_0.dtd">
+    "-//Checkstyle//DTD SuppressionFilter Configuration 1.0//EN"
+    "https://checkstyle.org/dtds/suppressions_1_0.dtd">
 <suppressions>
   <suppress checks="LeftCurly" files="Suppressed\.java"/>
   <suppress checks="EmptyBlock" files="Suppressed\.java"/>
diff --git a/src/it/MCHECKSTYLE-169/build-tools/src/main/resources/com/company/build-tools/checkstyle.xml b/src/it/MCHECKSTYLE-169/build-tools/src/main/resources/com/company/build-tools/checkstyle.xml
index bedb23f9..0ae6afec 100644
--- a/src/it/MCHECKSTYLE-169/build-tools/src/main/resources/com/company/build-tools/checkstyle.xml
+++ b/src/it/MCHECKSTYLE-169/build-tools/src/main/resources/com/company/build-tools/checkstyle.xml
@@ -20,8 +20,8 @@ under the License.
 -->
 
 <!DOCTYPE module PUBLIC
-    "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
-    "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
+    "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+    "https://checkstyle.org/dtds/configuration_1_3.dtd">
 <module name="Checker">
   <module name="SuppressionFilter">
     <property name="file" value="${checkstyle.suppressions.file}"/>
diff --git a/src/it/MCHECKSTYLE-173-with-charset/checkstyle-with-charset.xml b/src/it/MCHECKSTYLE-173-with-charset/checkstyle-with-charset.xml
index fa44873b..1eca506d 100644
--- a/src/it/MCHECKSTYLE-173-with-charset/checkstyle-with-charset.xml
+++ b/src/it/MCHECKSTYLE-173-with-charset/checkstyle-with-charset.xml
@@ -17,7 +17,7 @@ KIND, either express or implied.  See the License for the
 specific language governing permissions and limitations
 under the License.
 -->
-<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN" "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
+<!DOCTYPE module PUBLIC "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN" "https://checkstyle.org/dtds/configuration_1_3.dtd">
 <module name="Checker">
     <property name="charset" value="UTF-8"/>
 </module>
diff --git a/src/it/MCHECKSTYLE-173-without-charset/checkstyle-without-charset.xml b/src/it/MCHECKSTYLE-173-without-charset/checkstyle-without-charset.xml
index 3fa8e793..934c4da0 100644
--- a/src/it/MCHECKSTYLE-173-without-charset/checkstyle-without-charset.xml
+++ b/src/it/MCHECKSTYLE-173-without-charset/checkstyle-without-charset.xml
@@ -17,6 +17,6 @@ KIND, either express or implied.  See the License for the
 specific language governing permissions and limitations
 under the License.
 -->
-<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN" "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
+<!DOCTYPE module PUBLIC "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN" "https://checkstyle.org/dtds/configuration_1_3.dtd">
 <module name="Checker">
 </module>
diff --git a/src/it/MCHECKSTYLE-193/checkstyle.xml b/src/it/MCHECKSTYLE-193/checkstyle.xml
index 58868092..3bc02455 100644
--- a/src/it/MCHECKSTYLE-193/checkstyle.xml
+++ b/src/it/MCHECKSTYLE-193/checkstyle.xml
@@ -17,7 +17,7 @@
   ~ specific language governing permissions and limitations
   ~ under the License.
   -->
-<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.2//EN" "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
+<!DOCTYPE module PUBLIC "-//Checkstyle//DTD Checkstyle Configuration 1.2//EN" "https://checkstyle.org/dtds/configuration_1_2.dtd">
 <!-- 
 Checkstyle rules for Basis Technology.
 -->
diff --git a/src/it/MCHECKSTYLE-214-basedir-resource/checkstyle.xml b/src/it/MCHECKSTYLE-214-basedir-resource/checkstyle.xml
index 3db3bb76..20f78ab5 100644
--- a/src/it/MCHECKSTYLE-214-basedir-resource/checkstyle.xml
+++ b/src/it/MCHECKSTYLE-214-basedir-resource/checkstyle.xml
@@ -18,8 +18,8 @@ specific language governing permissions and limitations
 under the License.
 -->
 <!DOCTYPE module PUBLIC
-    "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
-    "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
+    "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+    "https://checkstyle.org/dtds/configuration_1_3.dtd">
 <module name="Checker">
     <module name="NewlineAtEndOfFile"/>
     <module name="Translation"/>
diff --git a/src/it/MCHECKSTYLE-219-no-license_failure/checkstyle.xml b/src/it/MCHECKSTYLE-219-no-license_failure/checkstyle.xml
index 7ff76e36..163bfc67 100644
--- a/src/it/MCHECKSTYLE-219-no-license_failure/checkstyle.xml
+++ b/src/it/MCHECKSTYLE-219-no-license_failure/checkstyle.xml
@@ -19,8 +19,8 @@ under the License.
 -->
 
 <!DOCTYPE module PUBLIC
-    "-//Puppy Crawl//DTD Check Configuration 1.2//EN"
-    "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
+    "-//Checkstyle//DTD Checkstyle Configuration 1.2//EN"
+    "https://checkstyle.org/dtds/configuration_1_2.dtd">
 
 <module name="Checker">
 
diff --git a/src/it/MCHECKSTYLE-338/checkstyle.xml b/src/it/MCHECKSTYLE-338/checkstyle.xml
index a8363c5c..82f727fd 100644
--- a/src/it/MCHECKSTYLE-338/checkstyle.xml
+++ b/src/it/MCHECKSTYLE-338/checkstyle.xml
@@ -17,7 +17,7 @@
   ~ specific language governing permissions and limitations
   ~ under the License.
   -->
-<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.2//EN" "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
+<!DOCTYPE module PUBLIC "-//Checkstyle//DTD Checkstyle Configuration 1.2//EN" "https://checkstyle.org/dtds/configuration_1_2.dtd">
 <module name="Checker">
   <module name="org.apache.maven.plugins.checkstyle.EmptyLoggingCheck">
     <property name="severity" value="ignore" />
diff --git a/src/it/MCHECKSTYLE-347/checkstyle.xml b/src/it/MCHECKSTYLE-347/checkstyle.xml
index 027c8a45..d7081e22 100644
--- a/src/it/MCHECKSTYLE-347/checkstyle.xml
+++ b/src/it/MCHECKSTYLE-347/checkstyle.xml
@@ -17,7 +17,7 @@
   ~ specific language governing permissions and limitations
   ~ under the License.
   -->
-<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.2//EN" "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
+<!DOCTYPE module PUBLIC "-//Checkstyle//DTD Checkstyle Configuration 1.2//EN" "https://checkstyle.org/dtds/configuration_1_2.dtd">
 <module name="Checker">
   <module name="JavadocPackage"/>
 </module>
diff --git a/src/it/multi-modules-aggregate/maven_checks.xml b/src/it/multi-modules-aggregate/maven_checks.xml
index 78fb6b3f..1fb5e94f 100644
--- a/src/it/multi-modules-aggregate/maven_checks.xml
+++ b/src/it/multi-modules-aggregate/maven_checks.xml
@@ -19,8 +19,8 @@ under the License.
 -->
 
 <!DOCTYPE module PUBLIC
-    "-//Puppy Crawl//DTD Check Configuration 1.2//EN"
-    "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
+    "-//Checkstyle//DTD Checkstyle Configuration 1.2//EN"
+    "https://checkstyle.org/dtds/configuration_1_2.dtd">
 
 <!--
   Checkstyle configuration that checks the Maven coding conventions from:
diff --git a/src/it/multimoduleproject/checkstyle-dekies.xml b/src/it/multimoduleproject/checkstyle-dekies.xml
index a9f6062b..95e8f7bf 100644
--- a/src/it/multimoduleproject/checkstyle-dekies.xml
+++ b/src/it/multimoduleproject/checkstyle-dekies.xml
@@ -17,7 +17,7 @@ KIND, either express or implied.  See the License for the
 specific language governing permissions and limitations
 under the License.
 -->
-<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.2//EN" "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
+<!DOCTYPE module PUBLIC "-//Checkstyle//DTD Checkstyle Configuration 1.2//EN" "https://checkstyle.org/dtds/configuration_1_2.dtd">
 
 <module name="DEKIES">
 	<property name="localeCountry" value="DE"/>
diff --git a/src/main/java/org/apache/maven/plugins/checkstyle/AbstractCheckstyleReport.java b/src/main/java/org/apache/maven/plugins/checkstyle/AbstractCheckstyleReport.java
index 04ccba11..29a5c5b9 100644
--- a/src/main/java/org/apache/maven/plugins/checkstyle/AbstractCheckstyleReport.java
+++ b/src/main/java/org/apache/maven/plugins/checkstyle/AbstractCheckstyleReport.java
@@ -445,8 +445,8 @@ public abstract class AbstractCheckstyleReport
      * Only used when you specify {@code checkstyleRules}.
      */
     @Parameter( defaultValue = "<?xml version=\"1.0\"?>\n"
-            + "<!DOCTYPE module PUBLIC \"-//Puppy Crawl//DTD Check Configuration 1.3//EN\"\n"
-            + "        \"http://www.puppycrawl.com/dtds/configuration_1_3.dtd\">\n" )
+            + "<!DOCTYPE module PUBLIC \"-//Checkstyle//DTD Checkstyle Configuration 1.3//EN\"\n"
+            + "        \"https://checkstyle.org/dtds/configuration_1_3.dtd\">\n" )
     private String checkstyleRulesHeader;
 
     /**
diff --git a/src/main/java/org/apache/maven/plugins/checkstyle/CheckstyleViolationCheckMojo.java b/src/main/java/org/apache/maven/plugins/checkstyle/CheckstyleViolationCheckMojo.java
index 9131b52f..44840b7b 100644
--- a/src/main/java/org/apache/maven/plugins/checkstyle/CheckstyleViolationCheckMojo.java
+++ b/src/main/java/org/apache/maven/plugins/checkstyle/CheckstyleViolationCheckMojo.java
@@ -454,8 +454,8 @@ public class CheckstyleViolationCheckMojo
      * Only used when you specify {@code checkstyleRules}.
      */
     @Parameter( defaultValue = "<?xml version=\"1.0\"?>\n"
-            + "<!DOCTYPE module PUBLIC \"-//Puppy Crawl//DTD Check Configuration 1.3//EN\"\n"
-            + "        \"http://www.puppycrawl.com/dtds/configuration_1_3.dtd\">\n" )
+            + "<!DOCTYPE module PUBLIC \"-//Checkstyle//DTD Checkstyle Configuration 1.3//EN\"\n"
+            + "        \"https://checkstyle.org/dtds/configuration_1_3.dtd\">\n" )
     private String checkstyleRulesHeader;
 
     /**
diff --git a/src/site/apt/examples/custom-developed-checkstyle.apt.vm b/src/site/apt/examples/custom-developed-checkstyle.apt.vm
index 447cc8ce..be3ae51b 100644
--- a/src/site/apt/examples/custom-developed-checkstyle.apt.vm
+++ b/src/site/apt/examples/custom-developed-checkstyle.apt.vm
@@ -92,8 +92,8 @@ mycompany-checkstyle-checks
 <?xml version="1.0" encoding="UTF-8"?>
 
 <!DOCTYPE checkstyle-packages PUBLIC
-  "-//Puppy Crawl//DTD Package Names 1.0//EN"
-  "http://www.puppycrawl.com/dtds/packages_1_0.dtd">
+  "-//Checkstyle//DTD Package Names Configuration 1.0//EN"
+  "https://checkstyle.org/dtds/packages_1_0.dtd">
 
 <checkstyle-packages>
   <package name="com.mycompany.checks"/>
@@ -203,8 +203,8 @@ mycompany-checkstyle-checks-1.0.jar
 <?xml version="1.0" ?>
 
 <!DOCTYPE module PUBLIC
-  "-//Puppy Crawl//DTD Check Configuration 1.2//EN"
-  "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
+  "-//Checkstyle//DTD Checkstyle Configuration 1.2//EN"
+  "https://checkstyle.org/dtds/configuration_1_2.dtd">
 
 <module name="Checker">
   <module name="TreeWalker">
diff --git a/src/site/apt/examples/custom-property-expansion.apt.vm b/src/site/apt/examples/custom-property-expansion.apt.vm
index 36692691..6a15be79 100644
--- a/src/site/apt/examples/custom-property-expansion.apt.vm
+++ b/src/site/apt/examples/custom-property-expansion.apt.vm
@@ -41,8 +41,8 @@ Using Custom Checkstyle Property Expansion Definitions
 <?xml version="1.0" ?>
 
 <!DOCTYPE module PUBLIC
-  "-//Puppy Crawl//DTD Check Configuration 1.2//EN"
-  "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
+  "-//Checkstyle//DTD Checkstyle Configuration 1.2//EN"
+  "https://checkstyle.org/dtds/configuration_1_2.dtd">
 
 <module name="Checker">
   <module name="TreeWalker">
diff --git a/src/site/apt/examples/suppressions-filter.apt.vm b/src/site/apt/examples/suppressions-filter.apt.vm
index f93f4b6d..576e4b26 100644
--- a/src/site/apt/examples/suppressions-filter.apt.vm
+++ b/src/site/apt/examples/suppressions-filter.apt.vm
@@ -37,8 +37,8 @@ Using a Suppressions Filter
 <?xml version="1.0"?>
 
 <!DOCTYPE suppressions PUBLIC
-     "-//Puppy Crawl//DTD Suppressions 1.0//EN"
-     "http://www.puppycrawl.com/dtds/suppressions_1_0.dtd">
+     "-//Checkstyle//DTD SuppressionFilter Configuration 1.0//EN"
+     "https://checkstyle.org/dtds/suppressions_1_0.dtd">
 
 <suppressions>
   <suppress checks="JavadocStyleCheck"