diff --git a/docs/src/main/asciidoc/verifier_contract.adoc b/docs/src/main/asciidoc/verifier_contract.adoc
index 935b183b8d..0094e93029 100644
--- a/docs/src/main/asciidoc/verifier_contract.adoc
+++ b/docs/src/main/asciidoc/verifier_contract.adoc
@@ -1662,7 +1662,7 @@ following code listing shows the `SingleTestGenerator` interface:
 
 [source,groovy]
 ----
-include::{verifier_core_path}/src/main/groovy/org/springframework/cloud/contract/verifier/builder/SingleTestGenerator.java[indent=0,lines=17..-1]
+include::{verifier_core_path}/src/main/groovy/org/springframework/cloud/contract/verifier/builder/SingleTestGenerator.groovy[indent=0,lines=17..-1]
 ----
 
 Again, you must provide a `spring.factories` file, such as the one shown in the following
diff --git a/spring-cloud-contract-verifier/pom.xml b/spring-cloud-contract-verifier/pom.xml
index 38c0ea8d11..d41c4d169f 100644
--- a/spring-cloud-contract-verifier/pom.xml
+++ b/spring-cloud-contract-verifier/pom.xml
@@ -209,13 +209,8 @@
 					<execution>
 						<goals>
 							<goal>addSources</goal>
-							<goal>addTestSources</goal>
-							<goal>generateStubs</goal>
 							<goal>compile</goal>
-							<goal>generateTestStubs</goal>
 							<goal>compileTests</goal>
-							<goal>removeStubs</goal>
-							<goal>removeTestStubs</goal>
 						</goals>
 					</execution>
 				</executions>
diff --git a/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/GeneratedClassDataForMethod.java b/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/GeneratedClassDataForMethod.groovy
similarity index 78%
rename from spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/GeneratedClassDataForMethod.java
rename to spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/GeneratedClassDataForMethod.groovy
index 0a341b0dbe..b49ed288bf 100644
--- a/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/GeneratedClassDataForMethod.java
+++ b/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/GeneratedClassDataForMethod.groovy
@@ -1,7 +1,7 @@
 /*
  * Copyright 2013-2018 the original author or authors.
  *
- * Licensed under the Apache License, Version 2.0 (the "License");
+ * Licensed under the Apache License, Version 2.0 (the "License")
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
@@ -14,34 +14,34 @@
  * limitations under the License.
  */
 
-package org.springframework.cloud.contract.verifier.builder;
+package org.springframework.cloud.contract.verifier.builder
 
 /**
  * @author Marcin Grzejszczak
  * @since
  */
 class GeneratedClassDataForMethod {
-	final SingleTestGenerator.GeneratedClassData generatedClassData;
-	final String methodName;
+	final SingleTestGenerator.GeneratedClassData generatedClassData
+	final String methodName
 
 	GeneratedClassDataForMethod(SingleTestGenerator.GeneratedClassData generatedClassData,
 			String methodName) {
-		this.generatedClassData = generatedClassData;
-		this.methodName = methodName;
+		this.generatedClassData = generatedClassData
+		this.methodName = methodName
 	}
 
 	private SingleTestGenerator.GeneratedClassData assertClassData() {
 		if (this.generatedClassData == null) {
-			throw new IllegalStateException("No metadata was found for the generated test class");
+			throw new IllegalStateException("No metadata was found for the generated test class")
 		}
-		return this.generatedClassData;
+		return this.generatedClassData
 	}
 
 	String className() {
-		return assertClassData().className;
+		return assertClassData().className
 	}
 
 	java.nio.file.Path testClassPath() {
-		return assertClassData().testClassPath;
+		return assertClassData().testClassPath
 	}
 }
diff --git a/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/SingleTestGenerator.java b/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/SingleTestGenerator.groovy
similarity index 74%
rename from spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/SingleTestGenerator.java
rename to spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/SingleTestGenerator.groovy
index 1f2de9e11d..84a55aded5 100644
--- a/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/SingleTestGenerator.java
+++ b/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/SingleTestGenerator.groovy
@@ -1,16 +1,16 @@
-package org.springframework.cloud.contract.verifier.builder;
+package org.springframework.cloud.contract.verifier.builder
 
-import java.util.Collection;
 
-import org.springframework.cloud.contract.verifier.config.ContractVerifierConfigProperties;
-import org.springframework.cloud.contract.verifier.file.ContractMetadata;
+import org.springframework.cloud.contract.verifier.config.ContractVerifierConfigProperties
+import org.springframework.cloud.contract.verifier.file.ContractMetadata 
 
 /**
  * Builds a single test.
  *
  * @since 1.1.0
  */
-public interface SingleTestGenerator {
+trait SingleTestGenerator {
+
 	/**
 	 * Creates contents of a single test class in which all test scenarios from
 	 * the contract metadata should be placed.
@@ -24,8 +24,8 @@ public interface SingleTestGenerator {
 	 * @deprecated use {@link SingleTestGenerator#buildClass(ContractVerifierConfigProperties, Collection, String, GeneratedClassData)}
 	 */
 	@Deprecated
-	String buildClass(ContractVerifierConfigProperties properties,
-			Collection<ContractMetadata> listOfFiles, String className, String classPackage, String includedDirectoryRelativePath);
+	abstract String buildClass(ContractVerifierConfigProperties properties,
+			Collection<ContractMetadata> listOfFiles, String className, String classPackage, String includedDirectoryRelativePath)
 
 	/**
 	 * Creates contents of a single test class in which all test scenarios from
@@ -37,9 +37,9 @@ public interface SingleTestGenerator {
 	 * @param includedDirectoryRelativePath - relative path to the included directory
 	 * @return contents of a single test class
 	 */
-	default String buildClass(ContractVerifierConfigProperties properties,
+	String buildClass(ContractVerifierConfigProperties properties,
 			Collection<ContractMetadata> listOfFiles, String includedDirectoryRelativePath, GeneratedClassData generatedClassData) {
-		return buildClass(properties, listOfFiles, generatedClassData.className, generatedClassData.classPackage, includedDirectoryRelativePath);
+		return buildClass(properties, listOfFiles, generatedClassData.className, generatedClassData.classPackage, includedDirectoryRelativePath)
 	}
 
 	/**
@@ -47,18 +47,18 @@ public interface SingleTestGenerator {
 	 *
 	 * @param properties - properties passed to the plugin
 	 */
-	String fileExtension(ContractVerifierConfigProperties properties);
+	abstract String fileExtension(ContractVerifierConfigProperties properties)
 
-	class GeneratedClassData {
-		public final String className;
-		public final String classPackage;
-		public final java.nio.file.Path testClassPath;
+	static class GeneratedClassData {
+		public final String className
+		public final String classPackage
+		public final java.nio.file.Path testClassPath
 
-		public GeneratedClassData(String className, String classPackage,
+		GeneratedClassData(String className, String classPackage,
 				java.nio.file.Path testClassPath) {
-			this.className = className;
-			this.classPackage = classPackage;
-			this.testClassPath = testClassPath;
+			this.className = className
+			this.classPackage = classPackage
+			this.testClassPath = testClassPath
 		}
 	}
 }