diff --git a/spec/models/budget/ballot_spec.rb b/spec/models/budget/ballot_spec.rb
index df31c9eae..ee6be74f1 100644
--- a/spec/models/budget/ballot_spec.rb
+++ b/spec/models/budget/ballot_spec.rb
@@ -16,9 +16,7 @@ describe Budget::Ballot do
 
       expect(ballot.total_amount_spent).to eq 30000
     end
-  end
 
-  describe "#amount_spent by heading" do
     it "returns the amount spent on all investments assigned to a specific heading" do
       heading = create(:budget_heading)
       inv1 = create(:budget_investment, :feasible, price: 10000, heading: heading)
@@ -40,4 +38,31 @@ describe Budget::Ballot do
     end
   end
 
-end
\ No newline at end of file
+  describe "#amount_available" do
+    it "returns how much is left after taking some investments" do
+      budget = create(:budget, price: 200000)
+      heading = create(:budget_heading, budget: budget)
+      inv1 = create(:budget_investment, :feasible, price: 10000, heading: heading)
+      inv2 = create(:budget_investment, :feasible, price: 20000, heading: create(:budget_heading))
+      inv3 = create(:budget_investment, :feasible, price: 25000)
+      inv4 = create(:budget_investment, :feasible, price: 40000, heading: heading)
+
+      inv1 = create(:budget_investment, :feasible, price: 10000)
+      inv2 = create(:budget_investment, :feasible, price: 20000)
+
+      ballot = create(:budget_ballot, budget: budget)
+      ballot.investments << inv1
+      ballot.investments << inv2
+
+      expect(ballot.amount_available(heading)).to eq 1000000
+      expect(ballot.amount_available(nil)).to eq 170000
+
+      ballot.investments << inv3
+      ballot.investments << inv4
+
+      expect(ballot.amount_available(heading)).to eq 960000
+      expect(ballot.amount_available(nil)).to eq 145000
+    end
+  end
+
+end