diff --git a/zone/npc.cpp b/zone/npc.cpp
index ff46c1331..1a4837721 100644
--- a/zone/npc.cpp
+++ b/zone/npc.cpp
@@ -2254,8 +2254,12 @@ void NPC::PetOnSpawn(NewSpawn_Struct* ns)
 		if (RuleB(Pets, UnTargetableSwarmPet))
 		{
 			ns->spawn.bodytype = 11;
-			if(!IsCharmed() && swarmOwner->IsClient())
-				sprintf(ns->spawn.lastName, "%s's Pet", swarmOwner->GetName());
+			if(!IsCharmed() && swarmOwner->IsClient()) {
+				std::string tmp_lastname = swarmOwner->GetName();
+				tmp_lastname += "'s Pet";
+				if (tmp_lastname.size() < sizeof(ns->spawn.lastName))
+					strn0cpy(ns->spawn.lastName, tmp_lastname.c_str(), sizeof(ns->spawn.lastName));
+			}
 		}
 	}
 	else if(GetOwnerID())
@@ -2267,7 +2271,10 @@ void NPC::PetOnSpawn(NewSpawn_Struct* ns)
 			if(client)
 			{
 				SetPetOwnerClient(true);
-				sprintf(ns->spawn.lastName, "%s's Pet", client->GetName());
+				std::string tmp_lastname = swarmOwner->GetName();
+				tmp_lastname += "'s Pet";
+				if (tmp_lastname.size() < sizeof(ns->spawn.lastName))
+					strn0cpy(ns->spawn.lastName, tmp_lastname.c_str(), sizeof(ns->spawn.lastName));
 			}
 		}
 	}