diff --git a/core/src/main/java/org/springframework/security/authorization/AuthorizationEventPublisher.java b/core/src/main/java/org/springframework/security/authorization/AuthorizationEventPublisher.java
index b230d70a971..9e738bff384 100644
--- a/core/src/main/java/org/springframework/security/authorization/AuthorizationEventPublisher.java
+++ b/core/src/main/java/org/springframework/security/authorization/AuthorizationEventPublisher.java
@@ -30,6 +30,7 @@
  * @since 5.7
  * @see AuthorizationManager
  */
+@FunctionalInterface
 public interface AuthorizationEventPublisher {
 
 	/**