diff --git a/docs/pom.xml b/docs/pom.xml
index 6ba42ac6..15ee3e9e 100644
--- a/docs/pom.xml
+++ b/docs/pom.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 		 xmlns="http://maven.apache.org/POM/4.0.0"
-		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
diff --git a/pom.xml b/pom.xml
index 39a4efec..5134d9fe 100644
--- a/pom.xml
+++ b/pom.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 		 xmlns="http://maven.apache.org/POM/4.0.0"
-		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 
 	<groupId>org.springframework.cloud</groupId>
diff --git a/spring-cloud-gateway-core/pom.xml b/spring-cloud-gateway-core/pom.xml
index 743f9dd2..5e3da135 100644
--- a/spring-cloud-gateway-core/pom.xml
+++ b/spring-cloud-gateway-core/pom.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 		 xmlns="http://maven.apache.org/POM/4.0.0"
-		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 
 	<parent>
diff --git a/spring-cloud-gateway-dependencies/pom.xml b/spring-cloud-gateway-dependencies/pom.xml
index 93c74dec..abf674ae 100644
--- a/spring-cloud-gateway-dependencies/pom.xml
+++ b/spring-cloud-gateway-dependencies/pom.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 		 xmlns="http://maven.apache.org/POM/4.0.0"
-		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<artifactId>spring-cloud-dependencies-parent</artifactId>
diff --git a/spring-cloud-gateway-mvc/pom.xml b/spring-cloud-gateway-mvc/pom.xml
index d764896b..226d4ba2 100644
--- a/spring-cloud-gateway-mvc/pom.xml
+++ b/spring-cloud-gateway-mvc/pom.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 		 xmlns="http://maven.apache.org/POM/4.0.0"
-		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 
 	<artifactId>spring-cloud-gateway-mvc</artifactId>
diff --git a/spring-cloud-gateway-rsocket/pom.xml b/spring-cloud-gateway-rsocket/pom.xml
index 28e24b6e..b4acbf68 100644
--- a/spring-cloud-gateway-rsocket/pom.xml
+++ b/spring-cloud-gateway-rsocket/pom.xml
@@ -17,7 +17,7 @@
   -->
 
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
diff --git a/spring-cloud-gateway-sample/pom.xml b/spring-cloud-gateway-sample/pom.xml
index 554c1d95..d5501f26 100644
--- a/spring-cloud-gateway-sample/pom.xml
+++ b/spring-cloud-gateway-sample/pom.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 		 xmlns="http://maven.apache.org/POM/4.0.0"
-		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 
 	<artifactId>spring-cloud-gateway-sample</artifactId>
diff --git a/spring-cloud-gateway-webflux/pom.xml b/spring-cloud-gateway-webflux/pom.xml
index 0bf76eae..e7b60cc4 100644
--- a/spring-cloud-gateway-webflux/pom.xml
+++ b/spring-cloud-gateway-webflux/pom.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 		 xmlns="http://maven.apache.org/POM/4.0.0"
-		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 
 	<artifactId>spring-cloud-gateway-webflux</artifactId>
diff --git a/spring-cloud-starter-gateway/pom.xml b/spring-cloud-starter-gateway/pom.xml
index 062daf73..7c0d86d1 100644
--- a/spring-cloud-starter-gateway/pom.xml
+++ b/spring-cloud-starter-gateway/pom.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 		 xmlns="http://maven.apache.org/POM/4.0.0"
-		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
diff --git a/src/checkstyle/checkstyle-suppressions.xml b/src/checkstyle/checkstyle-suppressions.xml
index 00a2ac62..9cfd624e 100644
--- a/src/checkstyle/checkstyle-suppressions.xml
+++ b/src/checkstyle/checkstyle-suppressions.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <!DOCTYPE suppressions PUBLIC
 		"-//Puppy Crawl//DTD Suppressions 1.1//EN"
-		"http://www.puppycrawl.com/dtds/suppressions_1_1.dtd">
+		"https://www.puppycrawl.com/dtds/suppressions_1_1.dtd">
 <suppressions>
 	<suppress files=".*AbstractFilterChain\.java" checks="LineLengthCheck"/>
 	<suppress files=".*AbstractNameValueGatewayFilterFactory\.java" checks="LineLengthCheck"/>