diff --git a/database/migrations/2016_02_01_135956_add_source_currency_to_expenses.php b/database/migrations/2016_02_01_135956_add_source_currency_to_expenses.php
index c39a722af0..f40ed0fea4 100644
--- a/database/migrations/2016_02_01_135956_add_source_currency_to_expenses.php
+++ b/database/migrations/2016_02_01_135956_add_source_currency_to_expenses.php
@@ -21,7 +21,7 @@ class AddSourceCurrencyToExpenses extends Migration
                 $table->renameColumn('currency_id', 'invoice_currency_id');
             }
 
-            $table->unsignedInteger('expense_currency_id')->nullable();
+            $table->unsignedInteger('expense_currency_id')->nullable()->index();
         });
 
         Schema::table('expenses', function (Blueprint $table) {