diff --git a/spring-web/src/main/java/org/springframework/http/server/ServletServerHttpRequest.java b/spring-web/src/main/java/org/springframework/http/server/ServletServerHttpRequest.java
index 7cebbd4af32..0cb338fa9c9 100644
--- a/spring-web/src/main/java/org/springframework/http/server/ServletServerHttpRequest.java
+++ b/spring-web/src/main/java/org/springframework/http/server/ServletServerHttpRequest.java
@@ -209,6 +209,7 @@ public class ServletServerHttpRequest implements ServerHttpRequest {
 	}
 
 	@Override
+	@Nullable
 	public Principal getPrincipal() {
 		return this.servletRequest.getUserPrincipal();
 	}
@@ -329,7 +330,6 @@ public class ServletServerHttpRequest implements ServerHttpRequest {
 		@Nullable
 		private transient Set<Entry<String, Object>> entrySet;
 
-
 		@Override
 		public int size() {
 			int size = 0;
@@ -464,4 +464,5 @@ public class ServletServerHttpRequest implements ServerHttpRequest {
 			return entrySet;
 		}
 	}
+
 }