diff --git a/src/wuttafarm/web/views/master.py b/src/wuttafarm/web/views/master.py
index 7ff165b..482bdf2 100644
--- a/src/wuttafarm/web/views/master.py
+++ b/src/wuttafarm/web/views/master.py
@@ -68,3 +68,20 @@ class WuttaFarmMasterView(MasterView):
                 )
             ]
         return []
+
+    def configure_form(self, form):
+        """ """
+        f = form
+        super().configure_form(f)
+
+        # farmos_uuid
+        if self.creating:
+            f.remove("farmos_uuid")
+        else:
+            f.set_readonly("farmos_uuid")
+
+        # drupal_id
+        if self.creating:
+            f.remove("drupal_id")
+        else:
+            f.set_readonly("drupal_id")