diff --git a/py/hexagram/icons.py b/py/hexagram/icons.py
index 8c952d4..d4d7920 100644
--- a/py/hexagram/icons.py
+++ b/py/hexagram/icons.py
@@ -37,7 +37,8 @@ class ISO7000Icon():
         self.surface = render_to_image(path, width, height, style)
 
     def __del__(self):
-        self.surface.finish()
+        if self.surface is not None:
+            self.surface.finish()
 
     def draw(self, cr: cairo.Context, x: float, y: float):
         cr.set_source_surface(self.surface, x, y)