diff --git a/beat/web/databases/admin.py b/beat/web/databases/admin.py
index 2d1b556e9244b896de3052cbc37ad6d42477eaae..35d43c911b2badfeda484110d7b92d487ee200a3 100755
--- a/beat/web/databases/admin.py
+++ b/beat/web/databases/admin.py
@@ -117,7 +117,10 @@ class DatabaseModelForm(forms.ModelForm):
 
         if 'declaration_file' in self.data and \
                 isinstance(self.data['declaration_file'], six.string_types):
-            self.data['declaration_file'] = ContentFile(self.data['declaration_file'], name='unsaved')
+            mutable_data = self.data.copy()
+            mutable_data['declaration_file'] = ContentFile(self.data['declaration_file'], name='unsaved')
+            self.data = mutable_data
+
 
 
 #----------------------------------------------------------