diff --git a/challenge-01/pom.xml b/challenge-01/pom.xml
index 8943d26..62fefcc 100644
--- a/challenge-01/pom.xml
+++ b/challenge-01/pom.xml
@@ -5,7 +5,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>3.5.8</version>
+		<version>4.0.1</version>
 		<relativePath/> <!-- lookup parent from repository -->
 	</parent>
 	<groupId>dev.cbos.o11yc</groupId>
diff --git a/challenge-02/pom.xml b/challenge-02/pom.xml
index 6995d6b..06528c3 100644
--- a/challenge-02/pom.xml
+++ b/challenge-02/pom.xml
@@ -5,7 +5,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>3.5.8</version>
+		<version>4.0.1</version>
 	</parent>
 	<groupId>dev.cbos.o11yc</groupId>
 	<artifactId>challenge-02</artifactId>