diff --git a/benchmark/mongodb/src/main/java/org/springframework/data/microbenchmark/mongodb/AfterConvertCallbacksBenchmark.java b/benchmark/mongodb/src/main/java/org/springframework/data/microbenchmark/mongodb/AfterConvertCallbacksBenchmark.java
index 60a31c1..4285dd1 100644
--- a/benchmark/mongodb/src/main/java/org/springframework/data/microbenchmark/mongodb/AfterConvertCallbacksBenchmark.java
+++ b/benchmark/mongodb/src/main/java/org/springframework/data/microbenchmark/mongodb/AfterConvertCallbacksBenchmark.java
@@ -99,7 +99,13 @@ public class AfterConvertCallbacksBenchmark extends AbstractMicrobenchmark {
 
 		@Bean
 		AfterConvertCallback<Person> afterConvertCallback() {
-			return (it, document, collection) -> {
+			return new PersonAfterConvertCallback();
+		}
+
+		private static class PersonAfterConvertCallback implements AfterConvertCallback<Person> {
+
+			@Override
+			public Person onAfterConvert(Person it, Document document, String collection) {
 
 				Person target = new Person();
 				target.id = it.id;
@@ -108,7 +114,7 @@ public class AfterConvertCallbacksBenchmark extends AbstractMicrobenchmark {
 
 				target.address = it.address;
 				return target;
-			};
+			}
 		}
 	}
 
diff --git a/benchmark/mongodb/src/main/java/org/springframework/data/microbenchmark/mongodb/CallbacksBenchmark.java b/benchmark/mongodb/src/main/java/org/springframework/data/microbenchmark/mongodb/CallbacksBenchmark.java
index 02962cb..5f408be 100644
--- a/benchmark/mongodb/src/main/java/org/springframework/data/microbenchmark/mongodb/CallbacksBenchmark.java
+++ b/benchmark/mongodb/src/main/java/org/springframework/data/microbenchmark/mongodb/CallbacksBenchmark.java
@@ -100,7 +100,13 @@ public class CallbacksBenchmark extends AbstractMicrobenchmark {
 
 		@Bean
 		BeforeConvertCallback<Person> convertCallback() {
-			return (it, document) -> {
+			return new PersonBeforeConvertCallback();
+		}
+
+		private static class PersonBeforeConvertCallback implements BeforeConvertCallback<Person> {
+
+			@Override
+			public Person onBeforeConvert(Person it, String document) {
 
 				Person target = new Person();
 				target.id = it.id;
@@ -109,7 +115,7 @@ public class CallbacksBenchmark extends AbstractMicrobenchmark {
 
 				target.address = it.address;
 				return target;
-			};
+			}
 		}
 	}
 }