diff --git a/spring-boot-autoconfigure/src/test/resources/templates/view.html b/spring-boot-autoconfigure/src/test/resources/templates/view.html
index accdaf1ea19..4ff0e133524 100644
--- a/spring-boot-autoconfigure/src/test/resources/templates/view.html
+++ b/spring-boot-autoconfigure/src/test/resources/templates/view.html
@@ -1,4 +1,4 @@
-
+
Content
diff --git a/spring-boot-samples/spring-boot-sample-devtools/src/main/resources/templates/hello.html b/spring-boot-samples/spring-boot-sample-devtools/src/main/resources/templates/hello.html
index 50c0bdb7c52..76b2c65e19a 100644
--- a/spring-boot-samples/spring-boot-sample-devtools/src/main/resources/templates/hello.html
+++ b/spring-boot-samples/spring-boot-sample-devtools/src/main/resources/templates/hello.html
@@ -1,6 +1,6 @@
Hello
diff --git a/spring-boot-samples/spring-boot-sample-devtools/src/main/resources/templates/layout.html b/spring-boot-samples/spring-boot-sample-devtools/src/main/resources/templates/layout.html
index 34ffeefca6c..704addd7cb5 100644
--- a/spring-boot-samples/spring-boot-sample-devtools/src/main/resources/templates/layout.html
+++ b/spring-boot-samples/spring-boot-sample-devtools/src/main/resources/templates/layout.html
@@ -1,6 +1,6 @@
+ xmlns:layout="https://www.ultraq.net.nz/web/thymeleaf/layout">
Layout
diff --git a/spring-boot-samples/spring-boot-sample-web-ui/src/main/resources/templates/layout.html b/spring-boot-samples/spring-boot-sample-web-ui/src/main/resources/templates/layout.html
index c2fd11c8368..8ad5e323c14 100644
--- a/spring-boot-samples/spring-boot-sample-web-ui/src/main/resources/templates/layout.html
+++ b/spring-boot-samples/spring-boot-sample-web-ui/src/main/resources/templates/layout.html
@@ -1,6 +1,6 @@
+ xmlns:layout="https://www.ultraq.net.nz/web/thymeleaf/layout">
Layout
Messages : Create
diff --git a/spring-boot-samples/spring-boot-sample-web-ui/src/main/resources/templates/messages/list.html b/spring-boot-samples/spring-boot-sample-web-ui/src/main/resources/templates/messages/list.html
index cd7e9a1828d..d50382825ce 100644
--- a/spring-boot-samples/spring-boot-sample-web-ui/src/main/resources/templates/messages/list.html
+++ b/spring-boot-samples/spring-boot-sample-web-ui/src/main/resources/templates/messages/list.html
@@ -1,6 +1,6 @@
Messages : View all
diff --git a/spring-boot-samples/spring-boot-sample-web-ui/src/main/resources/templates/messages/view.html b/spring-boot-samples/spring-boot-sample-web-ui/src/main/resources/templates/messages/view.html
index 5128aa4b9a7..85493452239 100644
--- a/spring-boot-samples/spring-boot-sample-web-ui/src/main/resources/templates/messages/view.html
+++ b/spring-boot-samples/spring-boot-sample-web-ui/src/main/resources/templates/messages/view.html
@@ -1,5 +1,5 @@
Messages : View