diff --git a/build.gradle b/build.gradle
index 6b45d6e399..2d3ab152fe 100644
--- a/build.gradle
+++ b/build.gradle
@@ -334,7 +334,7 @@ configure([rootProject] + javaProjects) { project ->
 	}
 
 	checkstyle {
-		toolVersion = "8.35"
+		toolVersion = "8.36"
 		configDirectory.set(rootProject.file("src/checkstyle"))
 	}
 
diff --git a/spring-context/src/main/java/org/springframework/validation/BindException.java b/spring-context/src/main/java/org/springframework/validation/BindException.java
index fa11f14529..afc0c5c2ae 100644
--- a/spring-context/src/main/java/org/springframework/validation/BindException.java
+++ b/spring-context/src/main/java/org/springframework/validation/BindException.java
@@ -229,6 +229,7 @@ public class BindException extends Exception implements BindingResult {
 	}
 
 	@Override
+	@Nullable
 	public Object getTarget() {
 		return this.bindingResult.getTarget();
 	}
diff --git a/spring-context/src/main/java/org/springframework/validation/MapBindingResult.java b/spring-context/src/main/java/org/springframework/validation/MapBindingResult.java
index cadd9f8b57..41860a4c1d 100644
--- a/spring-context/src/main/java/org/springframework/validation/MapBindingResult.java
+++ b/spring-context/src/main/java/org/springframework/validation/MapBindingResult.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2006 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -19,6 +19,7 @@ package org.springframework.validation;
 import java.io.Serializable;
 import java.util.Map;
 
+import org.springframework.lang.NonNull;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
@@ -52,11 +53,15 @@ public class MapBindingResult extends AbstractBindingResult implements Serializa
 	}
 
 
+	/**
+	 * Return the target Map to bind onto.
+	 */
 	public final Map<?, ?> getTargetMap() {
 		return this.target;
 	}
 
 	@Override
+	@NonNull
 	public final Object getTarget() {
 		return this.target;
 	}
diff --git a/spring-web/src/main/java/org/springframework/web/bind/support/WebExchangeBindException.java b/spring-web/src/main/java/org/springframework/web/bind/support/WebExchangeBindException.java
index a18e6f5b44..ff8d88c7ea 100644
--- a/spring-web/src/main/java/org/springframework/web/bind/support/WebExchangeBindException.java
+++ b/spring-web/src/main/java/org/springframework/web/bind/support/WebExchangeBindException.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -217,6 +217,7 @@ public class WebExchangeBindException extends ServerWebInputException implements
 	}
 
 	@Override
+	@Nullable
 	public Object getTarget() {
 		return this.bindingResult.getTarget();
 	}