diff --git a/src/java.base/share/classes/java/lang/Object.java b/src/java.base/share/classes/java/lang/Object.java
index b8bfdc3e3f9..d9813df57a4 100644
--- a/src/java.base/share/classes/java/lang/Object.java
+++ b/src/java.base/share/classes/java/lang/Object.java
@@ -237,6 +237,10 @@ public class Object {
 
     /**
      * {@return a string representation of the object}
+     *
+     * Satisfying this method's contract implies a non-{@code null}
+     * result must be returned.
+     *
      * @apiNote
      * In general, the
      * {@code toString} method returns a string that