diff --git a/src/020-objects/065-common-keys-of-unions-of-objects.problem.ts b/src/020-objects/065-common-keys-of-unions-of-objects.problem.ts
index 86b3367..971fe30 100644
--- a/src/020-objects/065-common-keys-of-unions-of-objects.problem.ts
+++ b/src/020-objects/065-common-keys-of-unions-of-objects.problem.ts
@@ -1 +1,61 @@
-// UserQuery | PostQuery
+import { expect, it } from "vitest";
+
+type User = {
+  id: string;
+  name: string;
+  age: number;
+  imageId: string;
+};
+
+type Organisation = {
+  id: string;
+  name: string;
+  address: string;
+  imageId: string;
+};
+
+const getAvatarImage = (entity: unknown) => {
+  {
+    // Should not be able to access properties that are
+    // not common to both types
+
+    // @ts-expect-error
+    entity.age;
+
+    // @ts-expect-error
+    entity.address;
+  }
+
+  return {
+    url: `https://via.placeholder.com/${entity.imageId}`,
+    alt: `${entity.name} Avatar`,
+  };
+};
+
+it("Should work for a user", () => {
+  const result = getAvatarImage({
+    id: "1",
+    name: "John",
+    age: 20,
+    imageId: "abc123",
+  });
+
+  expect(result).toEqual({
+    url: "https://via.placeholder.com/abc123",
+    alt: "John Avatar",
+  });
+});
+
+it("Should work for an organisation", () => {
+  const result = getAvatarImage({
+    id: "1",
+    name: "Total TypeScript",
+    address: "1 Main Street",
+    imageId: "abc123",
+  });
+
+  expect(result).toEqual({
+    url: "https://via.placeholder.com/abc123",
+    alt: "Total TypeScript Avatar",
+  });
+});
diff --git a/src/020-objects/065-common-keys-of-unions-of-objects.solution.ts b/src/020-objects/065-common-keys-of-unions-of-objects.solution.ts
new file mode 100644
index 0000000..ab6d337
--- /dev/null
+++ b/src/020-objects/065-common-keys-of-unions-of-objects.solution.ts
@@ -0,0 +1,61 @@
+import { expect, it } from "vitest";
+
+type User = {
+  id: string;
+  name: string;
+  age: number;
+  imageId: string;
+};
+
+type Organisation = {
+  id: string;
+  name: string;
+  address: string;
+  imageId: string;
+};
+
+const getAvatarImage = (entity: User | Organisation) => {
+  {
+    // Should not be able to access properties that are
+    // not common to both types
+
+    // @ts-expect-error
+    entity.age;
+
+    // @ts-expect-error
+    entity.address;
+  }
+
+  return {
+    url: `https://via.placeholder.com/${entity.imageId}`,
+    alt: `${entity.name} Avatar`,
+  };
+};
+
+it("Should work for a user", () => {
+  const result = getAvatarImage({
+    id: "1",
+    name: "John",
+    age: 20,
+    imageId: "abc123",
+  });
+
+  expect(result).toEqual({
+    url: "https://via.placeholder.com/abc123",
+    alt: "John Avatar",
+  });
+});
+
+it("Should work for an organisation", () => {
+  const result = getAvatarImage({
+    id: "1",
+    name: "Total TypeScript",
+    address: "1 Main Street",
+    imageId: "abc123",
+  });
+
+  expect(result).toEqual({
+    url: "https://via.placeholder.com/abc123",
+    alt: "Total TypeScript Avatar",
+  });
+});