diff --git a/topojson/mytypes.py b/topojson/mytypes.py
index 01186dd..e6eebc0 100644
--- a/topojson/mytypes.py
+++ b/topojson/mytypes.py
@@ -68,7 +68,7 @@ def geometry(self,geometry):
             return self.Polygon(geometry)
         elif geometry['type']== 'GeometryCollection':
             return self.GeometryCollection(geometry)
-    def point(self):
+    def point(self, coordinates):
         pass
     def line(self,coordinates):
         for coordinate in coordinates: