diff --git a/app/models/budget/ballot.rb b/app/models/budget/ballot.rb
index f93838dac..22ba6b64b 100644
--- a/app/models/budget/ballot.rb
+++ b/app/models/budget/ballot.rb
@@ -10,7 +10,9 @@ class Budget
     has_many :headings, -> { distinct }, through: :groups
 
     def add_investment(investment)
-      lines.create(investment: investment).persisted?
+      line = lines.create(investment: investment)
+
+      line if line.persisted?
     end
 
     def total_amount_spent
diff --git a/spec/models/poll/ballot_spec.rb b/spec/models/poll/ballot_spec.rb
index 981b7ba20..8c6741f9a 100644
--- a/spec/models/poll/ballot_spec.rb
+++ b/spec/models/poll/ballot_spec.rb
@@ -53,43 +53,43 @@ describe Poll::Ballot do
     describe "Money" do
       it "is not valid if insufficient funds" do
         investment.update!(price: heading.price + 1)
-        expect(poll_ballot.add_investment(investment.id)).to be false
+        expect(poll_ballot.add_investment(investment.id)).to be nil
       end
 
       it "is valid if sufficient funds" do
         investment.update!(price: heading.price - 1)
-        expect(poll_ballot.add_investment(investment.id)).to be true
+        expect(poll_ballot.add_investment(investment.id)).to be_truthy
       end
     end
 
     describe "Heading" do
       it "is not valid if investment heading is not valid" do
-        expect(poll_ballot.add_investment(investment.id)).to be true
+        expect(poll_ballot.add_investment(investment.id)).to be_truthy
 
         other_heading = create(:budget_heading, group: group, price: 10000000)
         other_investment = create(:budget_investment, :selected, price: 1000000, heading: other_heading)
 
-        expect(poll_ballot.add_investment(other_investment.id)).to be false
+        expect(poll_ballot.add_investment(other_investment.id)).to be nil
       end
 
       it "is valid if investment heading is valid" do
-        expect(poll_ballot.add_investment(investment.id)).to be true
+        expect(poll_ballot.add_investment(investment.id)).to be_truthy
 
         other_investment = create(:budget_investment, :selected, price: 1000000, heading: heading)
 
-        expect(poll_ballot.add_investment(other_investment.id)).to be true
+        expect(poll_ballot.add_investment(other_investment.id)).to be_truthy
       end
     end
 
     describe "Selectibility" do
       it "is not valid if investment is unselected" do
         investment.update!(selected: false)
-        expect(poll_ballot.add_investment(investment.id)).to be false
+        expect(poll_ballot.add_investment(investment.id)).to be nil
       end
 
       it "is valid if investment is selected" do
         investment.update!(selected: true, price: 20000)
-        expect(poll_ballot.add_investment(investment.id)).to be true
+        expect(poll_ballot.add_investment(investment.id)).to be_truthy
       end
     end
 
@@ -101,7 +101,7 @@ describe Poll::Ballot do
       end
 
       it "is valid if investment belongs to the poll's budget" do
-        expect(poll_ballot.add_investment(investment.id)).to be true
+        expect(poll_ballot.add_investment(investment.id)).to be_truthy
       end
     end
 
@@ -112,7 +112,7 @@ describe Poll::Ballot do
       end
 
       it "is valid if does not already exist" do
-        expect(poll_ballot.add_investment(investment.id)).to be true
+        expect(poll_ballot.add_investment(investment.id)).to be_truthy
       end
     end
   end