diff --git a/benchmarks/pom.xml b/benchmarks/pom.xml
index 565479fd7..48213fc30 100644
--- a/benchmarks/pom.xml
+++ b/benchmarks/pom.xml
@@ -16,7 +16,7 @@
   -->
 <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>
 
 	<name>Benchmarks</name>
diff --git a/docs/pom.xml b/docs/pom.xml
index 89262fef1..0c8de5bad 100644
--- a/docs/pom.xml
+++ b/docs/pom.xml
@@ -17,7 +17,7 @@
 
 <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 2f24d1461..016a51174 100644
--- a/pom.xml
+++ b/pom.xml
@@ -17,7 +17,7 @@
 
 <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-sleuth</artifactId>
diff --git a/spring-cloud-sleuth-core/pom.xml b/spring-cloud-sleuth-core/pom.xml
index f7f652bd2..4df8d6814 100644
--- a/spring-cloud-sleuth-core/pom.xml
+++ b/spring-cloud-sleuth-core/pom.xml
@@ -17,7 +17,7 @@
 
 <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-sleuth-core</artifactId>
diff --git a/spring-cloud-sleuth-core/src/test/resources/beans/applicationContext.xml b/spring-cloud-sleuth-core/src/test/resources/beans/applicationContext.xml
index 97a57f823..990f9785f 100644
--- a/spring-cloud-sleuth-core/src/test/resources/beans/applicationContext.xml
+++ b/spring-cloud-sleuth-core/src/test/resources/beans/applicationContext.xml
@@ -20,10 +20,10 @@
 	   xmlns:int="http://www.springframework.org/schema/integration"
 	   xmlns="http://www.springframework.org/schema/beans"
 	   xsi:schemaLocation="http://www.springframework.org/schema/beans
-	    http://www.springframework.org/schema/beans/spring-beans.xsd
+	    https://www.springframework.org/schema/beans/spring-beans.xsd
 	    http://www.springframework.org/schema/integration
-		http://www.springframework.org/schema/integration/spring-integration.xsd
-		http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task.xsd">
+		https://www.springframework.org/schema/integration/spring-integration.xsd
+		http://www.springframework.org/schema/task https://www.springframework.org/schema/task/spring-task.xsd">
 
 	<int:channel id="messagingChannel"/>
 
diff --git a/spring-cloud-sleuth-dependencies/pom.xml b/spring-cloud-sleuth-dependencies/pom.xml
index 0aa46c856..5e574e145 100644
--- a/spring-cloud-sleuth-dependencies/pom.xml
+++ b/spring-cloud-sleuth-dependencies/pom.xml
@@ -17,7 +17,7 @@
 
 <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-sleuth-samples/pom.xml b/spring-cloud-sleuth-samples/pom.xml
index 2612d2c45..e90434e45 100644
--- a/spring-cloud-sleuth-samples/pom.xml
+++ b/spring-cloud-sleuth-samples/pom.xml
@@ -17,7 +17,7 @@
 
 <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-sleuth-samples</artifactId>
diff --git a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-feign/pom.xml b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-feign/pom.xml
index bb06d533a..83d5c6c21 100644
--- a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-feign/pom.xml
+++ b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-feign/pom.xml
@@ -17,7 +17,7 @@
 
 <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-sleuth-sample-feign</artifactId>
diff --git a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-messaging/pom.xml b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-messaging/pom.xml
index 766cc4fb8..bbe022ce6 100644
--- a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-messaging/pom.xml
+++ b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-messaging/pom.xml
@@ -17,7 +17,7 @@
 
 <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-sleuth-sample-messaging</artifactId>
diff --git a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-ribbon/pom.xml b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-ribbon/pom.xml
index 333debe93..d5f669fda 100644
--- a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-ribbon/pom.xml
+++ b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-ribbon/pom.xml
@@ -17,7 +17,7 @@
 
 <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-sleuth-sample-ribbon</artifactId>
diff --git a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-test-core/pom.xml b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-test-core/pom.xml
index c3d89efaf..ae625b8d6 100644
--- a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-test-core/pom.xml
+++ b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-test-core/pom.xml
@@ -17,7 +17,7 @@
 
 <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-sleuth-sample-test-core</artifactId>
diff --git a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-websocket/pom.xml b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-websocket/pom.xml
index be9862e06..eac7b92b0 100644
--- a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-websocket/pom.xml
+++ b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-websocket/pom.xml
@@ -17,7 +17,7 @@
 
 <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-sleuth-sample-websocket</artifactId>
diff --git a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-zipkin/pom.xml b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-zipkin/pom.xml
index 584aa0223..a0616670b 100644
--- a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-zipkin/pom.xml
+++ b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-zipkin/pom.xml
@@ -17,7 +17,7 @@
 
 <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-sleuth-sample-zipkin</artifactId>
diff --git a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample/pom.xml b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample/pom.xml
index 11a8ffa10..0f022e596 100644
--- a/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample/pom.xml
+++ b/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample/pom.xml
@@ -17,7 +17,7 @@
 
 <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-sleuth-sample</artifactId>
diff --git a/spring-cloud-sleuth-zipkin/pom.xml b/spring-cloud-sleuth-zipkin/pom.xml
index f921976f9..e4eace65f 100644
--- a/spring-cloud-sleuth-zipkin/pom.xml
+++ b/spring-cloud-sleuth-zipkin/pom.xml
@@ -17,7 +17,7 @@
 
 <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-sleuth-zipkin</artifactId>
diff --git a/spring-cloud-starter-sleuth/pom.xml b/spring-cloud-starter-sleuth/pom.xml
index 86564a31e..d437c6cd8 100644
--- a/spring-cloud-starter-sleuth/pom.xml
+++ b/spring-cloud-starter-sleuth/pom.xml
@@ -17,7 +17,7 @@
 
 <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/spring-cloud-starter-zipkin/pom.xml b/spring-cloud-starter-zipkin/pom.xml
index d756a1559..a2791401f 100644
--- a/spring-cloud-starter-zipkin/pom.xml
+++ b/spring-cloud-starter-zipkin/pom.xml
@@ -17,7 +17,7 @@
 
 <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 2b2f25d0b..264dcd341 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=".*FinishedSpanHandlerTests.*" checks="LineLengthCheck"/>
 	<suppress files=".*GrpcTracingIntegrationTests.*" checks="LineLengthCheck"/>