diff --git a/db/migrate/20090913173236_create_nii_types.rb b/db/migrate/20090913173236_create_nii_types.rb
index 1d5940363..0f83405ac 100644
--- a/db/migrate/20090913173236_create_nii_types.rb
+++ b/db/migrate/20090913173236_create_nii_types.rb
@@ -8,6 +8,6 @@ def change
 
       t.timestamps
     end
-    add_index :nii_types, :name, unique: true
+    add_index :nii_types, :name, unique: true, if_not_exists: true
   end
 end