diff --git a/app/controllers/budgets/ballot/lines_controller.rb b/app/controllers/budgets/ballot/lines_controller.rb
index e341e07d1..64806f2c9 100644
--- a/app/controllers/budgets/ballot/lines_controller.rb
+++ b/app/controllers/budgets/ballot/lines_controller.rb
@@ -18,9 +18,7 @@ module Budgets
         load_investment
         load_heading
 
-        unless @ballot.add_investment(@investment)
-          head :bad_request
-        end
+        @ballot.add_investment(@investment)
       end
 
       def destroy
diff --git a/app/models/budget/ballot.rb b/app/models/budget/ballot.rb
index 6a4047aff..83e799d6f 100644
--- a/app/models/budget/ballot.rb
+++ b/app/models/budget/ballot.rb
@@ -9,7 +9,7 @@ class Budget
     has_many :headings, -> { uniq }, through: :groups
 
     def add_investment(investment)
-      lines.create!(investment: investment)
+      lines.create(investment: investment).persisted?
     end
 
     def total_amount_spent