diff --git a/sample-1-2/pom.xml b/sample-1-2/pom.xml
index 0a9909b..9e62672 100644
--- a/sample-1-2/pom.xml
+++ b/sample-1-2/pom.xml
@@ -11,7 +11,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.1.2.RELEASE</version>
+        <version>2.2.4.RELEASE</version>
         <relativePath />
     </parent>
 
diff --git a/sample-2-1/pom.xml b/sample-2-1/pom.xml
index f2c5587..5bef292 100644
--- a/sample-2-1/pom.xml
+++ b/sample-2-1/pom.xml
@@ -11,7 +11,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.1.2.RELEASE</version>
+        <version>2.2.4.RELEASE</version>
         <relativePath/>
     </parent>
 
diff --git a/sample-2-2/sample-2-2-jdbc-spring/pom.xml b/sample-2-2/sample-2-2-jdbc-spring/pom.xml
index a6db8ac..3d552dc 100644
--- a/sample-2-2/sample-2-2-jdbc-spring/pom.xml
+++ b/sample-2-2/sample-2-2-jdbc-spring/pom.xml
@@ -14,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.1.2.RELEASE</version>
+		<version>2.2.4.RELEASE</version>
 		<relativePath />
 	</parent>
 
diff --git a/sample-2-2/sample-2-2-jpa-spring-data/pom.xml b/sample-2-2/sample-2-2-jpa-spring-data/pom.xml
index 3e521de..d2f5d9e 100644
--- a/sample-2-2/sample-2-2-jpa-spring-data/pom.xml
+++ b/sample-2-2/sample-2-2-jpa-spring-data/pom.xml
@@ -14,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.1.2.RELEASE</version>
+		<version>2.2.4.RELEASE</version>
 		<relativePath />
 	</parent>
 
diff --git a/sample-2-3/sample-2-3-mongo-reactive/pom.xml b/sample-2-3/sample-2-3-mongo-reactive/pom.xml
index 416ae1f..72a2143 100644
--- a/sample-2-3/sample-2-3-mongo-reactive/pom.xml
+++ b/sample-2-3/sample-2-3-mongo-reactive/pom.xml
@@ -14,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.1.2.RELEASE</version>
+		<version>2.2.4.RELEASE</version>
 		<relativePath />
 	</parent>
 
diff --git a/sample-2-3/sample-2-3-mongo/pom.xml b/sample-2-3/sample-2-3-mongo/pom.xml
index 51beaa3..2b6ebae 100644
--- a/sample-2-3/sample-2-3-mongo/pom.xml
+++ b/sample-2-3/sample-2-3-mongo/pom.xml
@@ -14,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.1.2.RELEASE</version>
+		<version>2.2.4.RELEASE</version>
 		<relativePath />
 	</parent>
 
diff --git a/sample-3-1/pom.xml b/sample-3-1/pom.xml
index eaefd18..f449956 100644
--- a/sample-3-1/pom.xml
+++ b/sample-3-1/pom.xml
@@ -14,7 +14,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.1.2.RELEASE</version>
+        <version>2.2.4.RELEASE</version>
         <relativePath/>
     </parent>
 
diff --git a/sample-3-2/pom.xml b/sample-3-2/pom.xml
index ba8fafa..ed14a6c 100644
--- a/sample-3-2/pom.xml
+++ b/sample-3-2/pom.xml
@@ -20,7 +20,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.1.2.RELEASE</version>
+		<version>2.2.4.RELEASE</version>
 		<relativePath/>
 	</parent>