diff --git a/pymaster.py b/pymaster.py
index 949823c..7e2bde3 100755
--- a/pymaster.py
+++ b/pymaster.py
@@ -108,6 +108,7 @@ def clientQuery(self, data, addr):
 		info = data.split('\0')[1].strip('\\')
 		split = info.split('\\')
 
+		key      = None
 		protocol = None
 		gamedir  = 'valve'
 		clver    = None
@@ -125,6 +126,8 @@ def clientQuery(self, data, addr):
 					clver = v
 				elif k == 'protocol':
 					protocol = int(v)
+				elif k == 'key':
+					key = int(v, 16)
 				# somebody is playing :)
 				elif k == 'thisismypcid' or k == 'heydevelopersifyoureadthis':
 					self.fakeInfoForOldVersions(gamedir, addr)
@@ -139,6 +142,10 @@ def clientQuery(self, data, addr):
 			return
 
 		packet = MasterProtocol.queryPacketHeader
+
+		if key != None:
+			packet += b'\x7F' + pack('<I', key) + b'\x00'
+
 		for i in self.serverList:
 			if time() > i.die:
 				self.serverList.remove(i)