diff --git a/build.gradle b/build.gradle
index ab2dc638..e02a41d3 100644
--- a/build.gradle
+++ b/build.gradle
@@ -132,7 +132,6 @@ jreleaser {
 
 configure(subprojects) {
     apply plugin: 'java'
-    apply plugin: 'groovy'
     apply plugin: 'maven-publish'
 
     apply plugin: 'jacoco'
@@ -141,7 +140,8 @@ configure(subprojects) {
     description "${rootProject.description} - Module ${project.name}"
 
     dependencies {
-        implementation platform (libs.slf4j.bom)
+        implementation platform(libs.groovy.bom)
+        implementation platform(libs.slf4j.bom)
 
         testImplementation platform(libs.spock)
         testImplementation "org.spockframework:spock-core"
@@ -274,6 +274,7 @@ tasks.register("integrationTestOnly") {
 final String INTEGRATION_TEST_DIRECTORY = "integration-test"
 final String INTEGRATION_TEST_DIRECTORY_GRADLE_PLUGIN = "${INTEGRATION_TEST_DIRECTORY}/gradle-plugin"
 final String INTEGRATION_TEST_DIRECTORY_CLI = "${INTEGRATION_TEST_DIRECTORY}/cli"
+
 static void cleanBuild(String baseDirectory) {
     File integrationTestBuildDir = new File("${baseDirectory}/${Project.DEFAULT_BUILD_DIR_NAME}")
     if (integrationTestBuildDir.exists()) {
@@ -337,7 +338,7 @@ integrationTestCli.dependsOn(
         ':htmlSanityCheck-cli:installDist'
 )
 integrationTestCli.configure {
-    shouldRunAfter (':htmlSanityCheck-cli:check')
+    shouldRunAfter(':htmlSanityCheck-cli:check')
 }
 tasks.register("cleanIntegrationTestCli", Delete) {
     group("Build")
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 81a22f0e..f82d6a52 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -5,9 +5,12 @@ slf4j-version = '2.0.16'
 
 [libraries]
 commons-validator = 'commons-validator:commons-validator:1.9.0'
+# Use latest 3.x Groovy Version to use Spock for Groovy 3 as long as Gradle uses Groovy 3
+groovy-bom = 'org.codehaus.groovy:groovy-bom:3.0.22'
 jsoup = 'org.jsoup:jsoup:1.18.1'
 junit-vintage = { module = 'org.junit.vintage:junit-vintage-engine', version.ref = 'junit5-version' }
 lombok = 'org.projectlombok:lombok:1.18.34'
+mockito = "org.mockito:mockito-junit-jupiter:3.12.4"
 picocli-impl = { module = 'info.picocli:picocli', version.ref = "picocli-version" }
 picocli-annotationprocessor = { module = 'info.picocli:picocli-codegen', version.ref = "picocli-version" }
 slf4j-bom = { module = "org.slf4j:slf4j-bom", version.ref = "slf4j-version" }
diff --git a/htmlSanityCheck-cli/build.gradle b/htmlSanityCheck-cli/build.gradle
index 3fdcdf4b..edf797ee 100644
--- a/htmlSanityCheck-cli/build.gradle
+++ b/htmlSanityCheck-cli/build.gradle
@@ -1,11 +1,13 @@
 plugins {
     id 'application'
+    id 'groovy'
 }
 
 dependencies {
     implementation libs.picocli.impl
     annotationProcessor libs.picocli.annotationprocessor
 
+    implementation 'org.codehaus.groovy:groovy'
     implementation 'org.slf4j:slf4j-api'
     implementation 'org.slf4j:slf4j-simple'
 
diff --git a/htmlSanityCheck-cli/src/main/groovy/org/aim42/htmlsanitycheck/cli/Main.groovy b/htmlSanityCheck-cli/src/main/groovy/org/aim42/htmlsanitycheck/cli/Main.groovy
index ed5b080e..09dcc169 100644
--- a/htmlSanityCheck-cli/src/main/groovy/org/aim42/htmlsanitycheck/cli/Main.groovy
+++ b/htmlSanityCheck-cli/src/main/groovy/org/aim42/htmlsanitycheck/cli/Main.groovy
@@ -2,6 +2,7 @@ package org.aim42.htmlsanitycheck.cli
 
 import org.aim42.htmlsanitycheck.AllChecksRunner
 import org.aim42.htmlsanitycheck.Configuration
+import org.aim42.htmlsanitycheck.check.AllCheckers
 import org.slf4j.Logger
 import org.slf4j.LoggerFactory
 import picocli.CommandLine
@@ -87,12 +88,13 @@ class Main implements Runnable {
                 System.exit(1)
             }
 
-            var configuration = new Configuration()
-            configuration.addConfigurationItem(Configuration.ITEM_NAME_sourceDir, main.srcDir)
-            configuration.addConfigurationItem(Configuration.ITEM_NAME_sourceDocuments, srcDocuments)
-
             var resultsDirectory = new File(main.resultsDirectoryName)
-            configuration.addConfigurationItem((Configuration.ITEM_NAME_checkingResultsDir), resultsDirectory)
+            var configuration = Configuration.builder()
+                    .sourceDir(main.srcDir)
+                    .sourceDocuments(srcDocuments as Set)
+                    .checkingResultsDir(resultsDirectory)
+                    .checksToExecute(AllCheckers.CHECKER_CLASSES)
+                    .build()
 
             if (configuration.isValid()) {
                 // create output directory for checking results
diff --git a/htmlSanityCheck-core/build.gradle b/htmlSanityCheck-core/build.gradle
index 908b532f..03f0417d 100644
--- a/htmlSanityCheck-core/build.gradle
+++ b/htmlSanityCheck-core/build.gradle
@@ -9,8 +9,6 @@ dependencies {
         // Having a vulnerability here ...
         exclude group: 'commons-collections', module: 'commons-collections'
     }
-    implementation libs.slf4j.api
-    testImplementation libs.slf4j.nop
     implementation 'org.slf4j:slf4j-api'
     testImplementation 'org.slf4j:slf4j-nop'
     // jsoup is our awesome html parser, see jsoup.org
diff --git a/htmlSanityCheck-core/src/main/java/org/aim42/htmlsanitycheck/Configuration.java b/htmlSanityCheck-core/src/main/java/org/aim42/htmlsanitycheck/Configuration.java
index 098bcd6c..80c4426c 100644
--- a/htmlSanityCheck-core/src/main/java/org/aim42/htmlsanitycheck/Configuration.java
+++ b/htmlSanityCheck-core/src/main/java/org/aim42/htmlsanitycheck/Configuration.java
@@ -32,11 +32,16 @@ public class Configuration {
     File sourceDir;
     File checkingResultsDir;
     File junitResultsDir;
-    Boolean consoleReport;
-    Boolean failOnErrors;
-    Integer httpConnectionTimeout;
-    Boolean ignoreLocalhost;
-    Boolean ignoreIPAddresses;
+    @Builder.Default
+    Boolean consoleReport = false;
+    @Builder.Default
+    Boolean failOnErrors = false;
+    @Builder.Default
+    Integer httpConnectionTimeout = 5000;
+    @Builder.Default
+    Boolean ignoreLocalhost = false;
+    @Builder.Default
+    Boolean ignoreIPAddresses = false;
     /*
      * Explanation for configuring http status codes:
      * The standard http status codes are defined in class @link NetUtil and can
diff --git a/htmlSanityCheck-gradle-plugin/build.gradle b/htmlSanityCheck-gradle-plugin/build.gradle
index 8cf456c3..254b4f51 100755
--- a/htmlSanityCheck-gradle-plugin/build.gradle
+++ b/htmlSanityCheck-gradle-plugin/build.gradle
@@ -1,4 +1,6 @@
 plugins {
+    id 'groovy'
+
     id 'java-gradle-plugin'
     id 'jacoco-report-aggregation'
 
diff --git a/integration-test/gradle-plugin/build.gradle b/integration-test/gradle-plugin/build.gradle
index 419fe027..f5cb0214 100644
--- a/integration-test/gradle-plugin/build.gradle
+++ b/integration-test/gradle-plugin/build.gradle
@@ -68,7 +68,7 @@ buildReadmeGradlePlugin.dependsOn(buildReadmeRoot)
 //buildReadmeGradlePlugin.dependsOn(copyReadmeResources)
 
 htmlSanityCheck {
-    sourceDir file("build/docs")
+    sourceDir = file("../common/src/test/resources")
 
     checkingResultsDir = file("build/reports")
     failOnErrors = true