diff --git a/gerber/rs274x.py b/gerber/rs274x.py
index 76e5101..911b8ae 100644
--- a/gerber/rs274x.py
+++ b/gerber/rs274x.py
@@ -448,6 +448,7 @@ class GerberParser(object):
         else:
             aperture = self.macros[shape].build(modifiers)
 
+        aperture.units = self.settings.units
         self.apertures[d] = aperture
 
     def _evaluate_mode(self, stmt):