diff --git a/config/src/test/groovy/org/springframework/security/config/annotation/ObjectPostProcessorTests.java b/config/src/test/java/org/springframework/security/config/annotation/ObjectPostProcessorTests.java
similarity index 70%
rename from config/src/test/groovy/org/springframework/security/config/annotation/ObjectPostProcessorTests.java
rename to config/src/test/java/org/springframework/security/config/annotation/ObjectPostProcessorTests.java
index d1c96c1be7..ad93dc340e 100644
--- a/config/src/test/groovy/org/springframework/security/config/annotation/ObjectPostProcessorTests.java
+++ b/config/src/test/java/org/springframework/security/config/annotation/ObjectPostProcessorTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,16 +15,17 @@
  */
 package org.springframework.security.config.annotation;
 
-import static org.assertj.core.api.Assertions.assertThat;
-
 import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
 
 import org.junit.Test;
 
+import static org.assertj.core.api.Assertions.assertThat;
+
 /**
  * @author Rob Winch
+ * @author Josh Cummings
  *
  */
 public class ObjectPostProcessorTests {
@@ -34,17 +35,19 @@ public class ObjectPostProcessorTests {
 		assertThat((Object) PerformConversion.perform(new ArrayList<>()))
 				.isInstanceOf(LinkedList.class);
 	}
-}
 
-class ListToLinkedListObjectPostProcessor implements ObjectPostProcessor<List<?>> {
+	static class ListToLinkedListObjectPostProcessor implements ObjectPostProcessor<List<?>> {
 
-	public <O extends List<?>> O postProcess(O l) {
-		return (O) new LinkedList(l);
+		public <O extends List<?>> O postProcess(O l) {
+			return (O) new LinkedList(l);
+		}
+	}
+
+	static class PerformConversion {
+		public static List<?> perform(ArrayList<?> l) {
+			return new ListToLinkedListObjectPostProcessor().postProcess(l);
+		}
 	}
 }
 
-class PerformConversion {
-	public static List<?> perform(ArrayList<?> l) {
-		return new ListToLinkedListObjectPostProcessor().postProcess(l);
-	}
-}
+
diff --git a/config/src/test/groovy/org/springframework/security/config/annotation/SecurityConfigurerAdapterClosureTests.groovy b/config/src/test/java/org/springframework/security/config/annotation/SecurityConfigurerAdapterClosureTests.java
similarity index 51%
rename from config/src/test/groovy/org/springframework/security/config/annotation/SecurityConfigurerAdapterClosureTests.groovy
rename to config/src/test/java/org/springframework/security/config/annotation/SecurityConfigurerAdapterClosureTests.java
index 18e712c4a8..9565546229 100644
--- a/config/src/test/groovy/org/springframework/security/config/annotation/SecurityConfigurerAdapterClosureTests.groovy
+++ b/config/src/test/java/org/springframework/security/config/annotation/SecurityConfigurerAdapterClosureTests.java
@@ -1,11 +1,11 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * 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
  *
- *		https://www.apache.org/licenses/LICENSE-2.0
+ *      https://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -13,41 +13,49 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.security.config.annotation
+package org.springframework.security.config.annotation;
+
 
 import java.util.ArrayList;
 import java.util.List;
 
-import spock.lang.Specification
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
 
 /**
  * @author Rob Winch
+ * @author Josh Cummings
  *
  */
-class SecurityConfigurerAdapterClosureTests extends Specification {
-	ConcereteSecurityConfigurerAdapter conf = new ConcereteSecurityConfigurerAdapter()
+public class SecurityConfigurerAdapterClosureTests {
+	ConcereteSecurityConfigurerAdapter conf = new ConcereteSecurityConfigurerAdapter();
 
-	def "addPostProcessor closure"() {
-		setup:
-			SecurityBuilder<Object> builder = Mock()
-			conf.addObjectPostProcessor({ List l ->
-				l.add("a")
-				l
-			} as ObjectPostProcessor<List>)
-		when:
-			conf.init(builder)
-			conf.configure(builder)
-		then:
-			conf.list.contains("a")
+	@Test
+	public void addPostProcessorClosureWhenPostProcessThenGetsApplied() throws Exception {
+		SecurityBuilder<Object> builder = mock(SecurityBuilder.class);
+		this.conf.addObjectPostProcessor(new ObjectPostProcessor<List<String>>() {
+			@Override
+			public <O extends List<String>> O postProcess(O l) {
+				l.add("a");
+				return l;
+			}
+		});
+
+		this.conf.init(builder);
+		this.conf.configure(builder);
+
+		assertThat(this.conf.list).contains("a");
 	}
 
-	class ConcereteSecurityConfigurerAdapter extends
+	static class ConcereteSecurityConfigurerAdapter extends
 			SecurityConfigurerAdapter<Object, SecurityBuilder<Object>> {
 		private List<Object> list = new ArrayList<Object>();
 
 		@Override
 		public void configure(SecurityBuilder<Object> builder) throws Exception {
-			list = postProcess(list);
+			this.list = postProcess(this.list);
 		}
 
 		public ConcereteSecurityConfigurerAdapter list(List<Object> l) {