2to3 --fix=apply
diff --git a/Lib/fontTools/ttLib/tables/otBase.py b/Lib/fontTools/ttLib/tables/otBase.py
index d3f4eb3..523d2c8 100644
--- a/Lib/fontTools/ttLib/tables/otBase.py
+++ b/Lib/fontTools/ttLib/tables/otBase.py
@@ -429,7 +429,7 @@
 		return ref
 	
 	def writeStruct(self, format, values):
-		data = apply(struct.pack, (format,) + values)
+		data = struct.pack(*(format,) + values)
 		self.items.append(data)
 	
 	def writeData(self, data):