diff --git a/src/c3nav/mapdata/models/geometry/space.py b/src/c3nav/mapdata/models/geometry/space.py
index 243da518..fa8607c7 100644
--- a/src/c3nav/mapdata/models/geometry/space.py
+++ b/src/c3nav/mapdata/models/geometry/space.py
@@ -31,6 +31,8 @@ class SpaceGeometryMixin(GeometryMixin):
             color = self.get_color()
             if color:
                 result['color'] = color
+        if hasattr(self, 'opacity'):
+            result['opacity'] = self.opacity
         return result
 
     @property