diff --git a/wcs/wf/export_to_model.py b/wcs/wf/export_to_model.py
index 99e33315a..fa3d5ce6e 100644
--- a/wcs/wf/export_to_model.py
+++ b/wcs/wf/export_to_model.py
@@ -484,7 +484,6 @@ class ExportToModel(WorkflowStatusItem):
     directory_name = property(get_directory_name)
 
     def apply_template_to_formdata(self, formdata):
-        assert self.model_file
         kind = self.model_file_validation(self.model_file)
         if kind == 'rtf':
             outstream = self.apply_rtf_template_to_formdata(formdata)
@@ -733,6 +732,8 @@ class ExportToModel(WorkflowStatusItem):
         self.perform_real(formdata, formdata.evolution[-1])
 
     def perform_real(self, formdata, evo):
+        if not self.model_file:
+            return
         outstream = self.apply_template_to_formdata(formdata)
         filename = self.get_filename()
         content_type = self.model_file.content_type