diff --git a/lib/active_file/migration.rb b/lib/active_file/migration.rb
index a6f398106e4bf32533a2dbc83a6c0a058d631256..041e29ef3b2719a4cfb3668edc6dde26fb5b9c2a 100644
--- a/lib/active_file/migration.rb
+++ b/lib/active_file/migration.rb
@@ -8,7 +8,7 @@ def change
       t.string :checksum
       t.time :created_at
 
-      t.index [ :token ], unique: true
+      t.index [ :key ], unique: true
     end
   end
 end