diff --git a/build.gradle b/build.gradle
index e37be14..1986605 100644
--- a/build.gradle
+++ b/build.gradle
@@ -70,10 +70,7 @@ allprojects {
     }
 
     project.ext {
-        slf4jVersion = '1.7.32'
-        logbackVersion = '1.2.9'
         junitVersion = '5.8.2'
-        picocliVersion = '4.6.2'
         rootConfigDir = new File(rootDir, 'config')
         gitCommit = getGitCommit()
         isContinuousIntegrationEnvironment = Boolean.parseBoolean(System.getenv('CI'))
diff --git a/sop-java-picocli/build.gradle b/sop-java-picocli/build.gradle
index 81183a0..247c74f 100644
--- a/sop-java-picocli/build.gradle
+++ b/sop-java-picocli/build.gradle
@@ -15,7 +15,7 @@ dependencies {
     testImplementation 'org.mockito:mockito-core:4.2.0'
 
     implementation(project(":sop-java"))
-    implementation "info.picocli:picocli:$picocliVersion"
+    implementation "info.picocli:picocli:4.6.2"
 
     // https://mvnrepository.com/artifact/com.google.code.findbugs/jsr305
     implementation group: 'com.google.code.findbugs', name: 'jsr305', version: '3.0.2'