diff --git a/migen/bus/transactions.py b/migen/bus/transactions.py
index 002344dee..a3dd48405 100644
--- a/migen/bus/transactions.py
+++ b/migen/bus/transactions.py
@@ -1,13 +1,14 @@
 from migen.fhdl.structure import bits_for
 
 class Transaction:
-	def __init__(self, address, data=0, sel=None):
+	def __init__(self, address, data=0, sel=None, busname=None):
 		self.address = address
 		self.data = data
 		if sel is None:
 			bytes = (bits_for(data) + 7)//8
 			sel = 2**bytes - 1
 		self.sel = sel
+		self.busname = busname
 		self.latency = 0
 	
 	def __str__(self):