diff --git a/build.gradle b/build.gradle
index d5c05d11..4ae3f6b6 100644
--- a/build.gradle
+++ b/build.gradle
@@ -4,6 +4,8 @@ plugins {
 
 ext {
 	moduleProjects = [project(":spring-graphql"), project(":spring-graphql-test")]
+	bootVersion = "2.5.4"
+	graphQlJavaVersion = "17.2"
 }
 
 description = "Spring GraphQL"
@@ -42,7 +44,7 @@ configure(moduleProjects) {
 			mavenBom "org.junit:junit-bom:5.7.2"
 		}
 		dependencies {
-			dependency 'com.graphql-java:graphql-java:17.2'
+			dependency "com.graphql-java:graphql-java:${graphQlJavaVersion}"
 			dependency 'org.assertj:assertj-core:3.20.2'
 			dependencySet(group: 'org.apache.logging.log4j', version: '2.14.1') {
 				entry 'log4j-api'
diff --git a/graphql-spring-boot-starter/build.gradle b/graphql-spring-boot-starter/build.gradle
index ec6d0e77..43383d60 100644
--- a/graphql-spring-boot-starter/build.gradle
+++ b/graphql-spring-boot-starter/build.gradle
@@ -1,7 +1,7 @@
 import org.springframework.boot.gradle.plugin.SpringBootPlugin
 
 plugins {
-	id 'org.springframework.boot' version '2.5.4' apply false
+	id 'org.springframework.boot' version "${bootVersion}" apply false
 	id 'java-library'
 }
 
@@ -24,7 +24,7 @@ dependencyManagement {
 
 dependencies {
 	api project(':spring-graphql')
-	api 'com.graphql-java:graphql-java:17.2'
+	api "com.graphql-java:graphql-java:${graphQlJavaVersion}"
 	api 'io.projectreactor:reactor-core'
 	api 'org.springframework:spring-context'
 	api 'org.springframework.boot:spring-boot-starter'
diff --git a/samples/webflux-security/build.gradle b/samples/webflux-security/build.gradle
index f220b6fd..0b4e2417 100644
--- a/samples/webflux-security/build.gradle
+++ b/samples/webflux-security/build.gradle
@@ -1,5 +1,5 @@
 plugins {
-	id 'org.springframework.boot' version '2.5.4'
+	id 'org.springframework.boot' version "${bootVersion}"
 	id 'java'
 }
 group = 'com.example'
diff --git a/samples/webflux-websocket/build.gradle b/samples/webflux-websocket/build.gradle
index 24628b3b..7ab7f608 100644
--- a/samples/webflux-websocket/build.gradle
+++ b/samples/webflux-websocket/build.gradle
@@ -1,5 +1,5 @@
 plugins {
-	id 'org.springframework.boot' version '2.5.4'
+	id 'org.springframework.boot' version "${bootVersion}"
 	id 'java'
 }
 group = 'com.example'
diff --git a/samples/webmvc-http-security/build.gradle b/samples/webmvc-http-security/build.gradle
index 89817cd9..7090966d 100644
--- a/samples/webmvc-http-security/build.gradle
+++ b/samples/webmvc-http-security/build.gradle
@@ -1,5 +1,5 @@
 plugins {
-	id 'org.springframework.boot' version '2.5.4'
+	id 'org.springframework.boot' version "${bootVersion}"
 	id 'java'
 }
 group = 'com.example'
diff --git a/samples/webmvc-http/build.gradle b/samples/webmvc-http/build.gradle
index 7bda974f..cdc6ce02 100644
--- a/samples/webmvc-http/build.gradle
+++ b/samples/webmvc-http/build.gradle
@@ -1,5 +1,5 @@
 plugins {
-	id 'org.springframework.boot' version '2.5.4'
+	id 'org.springframework.boot' version "${bootVersion}"
 	id 'java'
 }
 group = 'com.example'