diff --git a/src/main/java/org/springframework/samples/petclinic/owner/PetController.java b/src/main/java/org/springframework/samples/petclinic/owner/PetController.java
index b58c1ba0059..6c37f057d17 100644
--- a/src/main/java/org/springframework/samples/petclinic/owner/PetController.java
+++ b/src/main/java/org/springframework/samples/petclinic/owner/PetController.java
@@ -138,7 +138,7 @@ public String processUpdateForm(@Valid Pet pet, BindingResult result, Owner owne
 		// checking if the pet name already exist for the owner
 		if (StringUtils.hasText(petName)) {
 			Pet existingPet = owner.getPet(petName.toLowerCase(), false);
-			if (existingPet != null && existingPet.getId().equals(pet.getId())) {
+			if (existingPet != null && !existingPet.getId().equals(pet.getId())) {
 				result.rejectValue("name", "duplicate", "already exists");
 			}
 		}