diff --git a/acl/src/main/java/org/springframework/security/acls/domain/PrincipalSid.java b/acl/src/main/java/org/springframework/security/acls/domain/PrincipalSid.java
index a1085f5ef0..005f3c1d90 100644
--- a/acl/src/main/java/org/springframework/security/acls/domain/PrincipalSid.java
+++ b/acl/src/main/java/org/springframework/security/acls/domain/PrincipalSid.java
@@ -53,7 +53,7 @@ public class PrincipalSid implements Sid {
 			this.principal = ((UserDetails) authentication.getPrincipal()).getUsername();
 		}
 		else {
-			this.principal = authentication.getPrincipal().toString();
+			this.principal = authentication.getName();
 		}
 	}