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 78339e9..9c6e98c 100644
--- a/src/main/java/org/springframework/samples/petclinic/owner/PetController.java
+++ b/src/main/java/org/springframework/samples/petclinic/owner/PetController.java
@@ -60,9 +60,7 @@ public Collection<PetType> populatePetTypes() {
 	public Owner findOwner(@PathVariable("ownerId") int ownerId) {
 
 		Owner owner = this.owners.findById(ownerId);
-		if (owner == null) {
-			throw new IllegalArgumentException("Owner ID not found: " + ownerId);
-		}
+		ControllerValidation.ValidateNotNull(owner, "Owner");
 		return owner;
 	}