diff --git a/lib/xmet/geo.py b/lib/xmet/geo.py
index 50c0509..e9cc4ef 100644
--- a/lib/xmet/geo.py
+++ b/lib/xmet/geo.py
@@ -27,13 +27,14 @@ class PointSequence(list):
 
         self.poly = None
 
-        for point in points:
-            typeof = type(point)
+        if points is not None:
+            for point in points:
+                typeof = type(point)
 
-            if typeof is tuple:
-                self.add(*point)
-            elif typeof is shapely.Point:
-                self.append(point)
+                if typeof is tuple:
+                    self.add(*point)
+                elif typeof is shapely.Point:
+                    self.append(point)
 
     def add(self, lon: float, lat: float):
         self.append(shapely.Point(lon, lat))