diff --git a/zone/client_process.cpp b/zone/client_process.cpp
index 55843e724..632f953d7 100644
--- a/zone/client_process.cpp
+++ b/zone/client_process.cpp
@@ -1194,6 +1194,12 @@ void Client::OPMoveCoin(const EQApplicationPacket* app)
 	int32 *from_bucket = 0, *to_bucket = 0;
 	Mob* trader = trade->With();
 
+	// if amount < 0, client is sending a malicious packet
+	if (mc->amount < 0)
+	{
+		return;
+	}
+	
 	// could just do a range, but this is clearer and explicit
 	if
 	(