diff --git a/apps/app/src/components/template-library/template-card-pie.test.tsx b/apps/app/src/components/template-library/template-card-pie.test.tsx
new file mode 100644
index 0000000..63305d8
--- /dev/null
+++ b/apps/app/src/components/template-library/template-card-pie.test.tsx
@@ -0,0 +1,34 @@
+import { afterEach, expect, it, vi } from "vitest";
+import { cleanup, render } from "@testing-library/react";
+import { TemplateCard } from "./template-card";
+afterEach(cleanup);
+function preview(data: { label: string; value: number }[]) {
+  return render(<TemplateCard id="pie" name="Share" description="" html=""
+    componentType="pieChart" componentData={{ data }} dataDescription="" version={1} onApply={vi.fn()} />)
+    .container.querySelector("svg")!;
+}
+it.each([
+  [[{ label: "Only category", value: 10 }], "#3b82f6"],
+  [[{ label: "Empty", value: 0 }, { label: "All revenue", value: 10 }, { label: "Other", value: 0 }], "#8b5cf6"],
+] as const)("draws a full disk when one category represents the entire total", (data, color) => {
+  const svg = preview([...data]);
+  const disk = svg.querySelector("circle");
+  expect(disk).not.toBeNull();
+  expect(Number(disk!.getAttribute("cx"))).toBe(60);
+  expect(Number(disk!.getAttribute("cy"))).toBe(60);
+  expect(Number(disk!.getAttribute("r"))).toBe(50);
+  expect(disk!.getAttribute("fill")).toBe(color);
+});
+it("retains separate slices for multiple positive categories", () => {
+  const svg = preview([{ label: "First", value: 3 }, { label: "Second", value: 1 }]);
+  expect(svg.querySelectorAll("path")).toHaveLength(2);
+  expect(svg.querySelector("circle")).toBeNull();
+});
+
+it.each([
+  { data: [] },
+  { data: [{ label: "Only empty category", value: 0 }] },
+  { data: [{ label: "First", value: 0 }, { label: "Second", value: 0 }] },
+])("keeps empty and zero-total previews unpainted", ({ data }) => {
+  expect(preview(data)).toBeNull();
+});
diff --git a/apps/app/src/components/template-library/template-card.tsx b/apps/app/src/components/template-library/template-card.tsx
index 23b9824..2c0cfbd 100644
--- a/apps/app/src/components/template-library/template-card.tsx
+++ b/apps/app/src/components/template-library/template-card.tsx
@@ -67,6 +67,10 @@ function PieChartPreview({ data }: { data: { label: string; value: number }[] })
     return acc;
   }, []);
   const slices = data.map((d, i) => {
+    // A full SVG arc with coincident endpoints has no painted area.
+    if (d.value === total) {
+      return <circle key={i} cx={cx} cy={cy} r={r} fill={CHART_COLORS[i % CHART_COLORS.length]} />;
+    }
     const startAngle = ((cumulativeAngles[i] - d.value) / total) * 2 * Math.PI - Math.PI / 2;
     const endAngle = (cumulativeAngles[i] / total) * 2 * Math.PI - Math.PI / 2;
     const largeArc = d.value / total > 0.5 ? 1 : 0;