diff --git a/apps/pr-reviewer/fixtures/demo-pr/loyalty.test.ts b/apps/pr-reviewer/fixtures/demo-pr/loyalty.test.ts
index 25bb6b2..ef85f65 100644
--- a/apps/pr-reviewer/fixtures/demo-pr/loyalty.test.ts
+++ b/apps/pr-reviewer/fixtures/demo-pr/loyalty.test.ts
@@ -41,4 +41,8 @@ describe('pointsFor', () => {
   it('returns a whole number', () => {
     expect(Number.isInteger(pointsFor(777))).toBe(true);
   });
+
+  it('awards nothing for a refund', () => {
+    expect(pointsFor(-10_000)).toBe(0);
+  });
 });
diff --git a/apps/pr-reviewer/fixtures/demo-pr/loyalty.ts b/apps/pr-reviewer/fixtures/demo-pr/loyalty.ts
index de0d988..a796ce0 100644
--- a/apps/pr-reviewer/fixtures/demo-pr/loyalty.ts
+++ b/apps/pr-reviewer/fixtures/demo-pr/loyalty.ts
@@ -1,4 +1,7 @@
-/** One and a half points per whole dollar spent, rounded once after the multiplier. */
+/** One and a half points per whole dollar spent, rounded once after the multiplier. Refunds earn nothing. */
 export function pointsFor(totalCents: number): number {
+  if (totalCents < 0) {
+    return 0;
+  }
   return Math.round((totalCents / 100) * 1.5);
 }