diff --git a/chapter01/pom.xml b/chapter01/pom.xml
index 581d6c07..7ec6e0c3 100644
--- a/chapter01/pom.xml
+++ b/chapter01/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>                    <!--2-->
+        <version>2.5.2</version>                    <!--2-->
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter02/pom.xml b/chapter02/pom.xml
index 52f92cce..2ea79462 100644
--- a/chapter02/pom.xml
+++ b/chapter02/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>                    <!--2-->
+        <version>2.5.2</version>                    <!--2-->
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter03-jdbc/pom.xml b/chapter03-jdbc/pom.xml
index fd11cf0e..8576d38d 100644
--- a/chapter03-jdbc/pom.xml
+++ b/chapter03-jdbc/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE
+        <version>2.5.2
         </version> <!-- Sticking with 2.0.0.RELEASE for now. Problem with GeneratedKeyHolder in 2.0.1.RELEASE and higher. -->
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
diff --git a/chapter03-jpa/pom.xml b/chapter03-jpa/pom.xml
index 7765784b..0f9cea64 100644
--- a/chapter03-jpa/pom.xml
+++ b/chapter03-jpa/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter04/pom.xml b/chapter04/pom.xml
index 97321a6f..7faaef45 100644
--- a/chapter04/pom.xml
+++ b/chapter04/pom.xml
@@ -11,7 +11,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter05/pom.xml b/chapter05/pom.xml
index e514ee4e..c2fa9485 100644
--- a/chapter05/pom.xml
+++ b/chapter05/pom.xml
@@ -11,7 +11,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter06/pom.xml b/chapter06/pom.xml
index 21c9abf3..0188f45d 100644
--- a/chapter06/pom.xml
+++ b/chapter06/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath/>
     </parent>
 
diff --git a/chapter07/pom.xml b/chapter07/pom.xml
index dd51594d..783e7dfd 100644
--- a/chapter07/pom.xml
+++ b/chapter07/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath/>
     </parent>
 
diff --git a/chapter08/pom.xml b/chapter08/pom.xml
index 6967b15b..31e3bcab 100644
--- a/chapter08/pom.xml
+++ b/chapter08/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath/>
     </parent>
 
diff --git a/chapter09-flow/pom.xml b/chapter09-flow/pom.xml
index 914a25e1..92c680e5 100644
--- a/chapter09-flow/pom.xml
+++ b/chapter09-flow/pom.xml
@@ -15,7 +15,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath /> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter09/pom.xml b/chapter09/pom.xml
index f0d83d75..85339c22 100644
--- a/chapter09/pom.xml
+++ b/chapter09/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath/>
     </parent>
 
diff --git a/chapter10/pom.xml b/chapter10/pom.xml
index d18cf1bc..64080cbf 100644
--- a/chapter10/pom.xml
+++ b/chapter10/pom.xml
@@ -7,7 +7,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath /> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter11-12-cassandra/pom.xml b/chapter11-12-cassandra/pom.xml
index 2f206438..4064c238 100644
--- a/chapter11-12-cassandra/pom.xml
+++ b/chapter11-12-cassandra/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath/>
     </parent>
 
diff --git a/chapter11-12-mongodb/pom.xml b/chapter11-12-mongodb/pom.xml
index eb4ecab2..7ee27a4f 100644
--- a/chapter11-12-mongodb/pom.xml
+++ b/chapter11-12-mongodb/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath/>
     </parent>
 
diff --git a/chapter13/pom.xml b/chapter13/pom.xml
index 7a863024..22c0cf7e 100644
--- a/chapter13/pom.xml
+++ b/chapter13/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath /> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter14-greettings/pom.xml b/chapter14-greettings/pom.xml
index 30464616..136c823c 100644
--- a/chapter14-greettings/pom.xml
+++ b/chapter14-greettings/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter14/pom.xml b/chapter14/pom.xml
index bfad66c2..d1e2d15e 100644
--- a/chapter14/pom.xml
+++ b/chapter14/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath /> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter15/pom.xml b/chapter15/pom.xml
index 0972ec7f..f6176deb 100644
--- a/chapter15/pom.xml
+++ b/chapter15/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath /> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter16/pom.xml b/chapter16/pom.xml
index fd1eb60d..95a7bd54 100644
--- a/chapter16/pom.xml
+++ b/chapter16/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath /> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter17/pom.xml b/chapter17/pom.xml
index aabf1898..d338769f 100644
--- a/chapter17/pom.xml
+++ b/chapter17/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath /> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter18/pom.xml b/chapter18/pom.xml
index ed5db836..9e6f52a7 100644
--- a/chapter18/pom.xml
+++ b/chapter18/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath /> <!-- lookup parent from repository -->
     </parent>
 
diff --git a/chapter19/pom.xml b/chapter19/pom.xml
index c1f0fc8c..46357fa0 100644
--- a/chapter19/pom.xml
+++ b/chapter19/pom.xml
@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.0.4.RELEASE</version>
+        <version>2.5.2</version>
         <relativePath /> <!-- lookup parent from repository -->
     </parent>