diff --git a/src/Avatar.test.tsx b/src/Avatar.test.tsx
new file mode 100644
index 00000000..9df6384c
--- /dev/null
+++ b/src/Avatar.test.tsx
@@ -0,0 +1,122 @@
+/*
+Copyright 2024 New Vector Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only
+Please see LICENSE in the repository root for full details.
+*/
+
+import { afterEach, expect, test, vi } from "vitest";
+import { render, screen } from "@testing-library/react";
+import { MatrixClient } from "matrix-js-sdk/src/client";
+import { FC, PropsWithChildren } from "react";
+
+import { ClientContextProvider } from "./ClientContext";
+import { Avatar } from "./Avatar";
+import { mockMatrixRoomMember } from "./utils/test";
+
+const TestComponent: FC<PropsWithChildren<{ client: MatrixClient }>> = ({
+  client,
+  children,
+}) => {
+  return (
+    <ClientContextProvider
+      value={{
+        state: "valid",
+        disconnected: false,
+        supportedFeatures: {
+          reactions: true,
+        },
+        setClient: vi.fn(),
+        authenticated: {
+          client,
+          isPasswordlessUser: true,
+          changePassword: vi.fn(),
+          logout: vi.fn(),
+        },
+      }}
+    >
+      {children}
+    </ClientContextProvider>
+  );
+};
+
+afterEach(() => {
+  vi.unstubAllGlobals();
+});
+
+test("should just render a placeholder when the user has no avatar", () => {
+  const client = vi.mocked<MatrixClient>({
+    getAccessToken: () => "my-access-token",
+    mxcUrlToHttp: () => vi.fn(),
+  } as unknown as MatrixClient);
+
+  vi.spyOn(client, "mxcUrlToHttp");
+  const member = mockMatrixRoomMember({
+    userId: "@alice:example.org",
+    getMxcAvatarUrl: () => undefined,
+  });
+  const displayName = "Alice";
+  render(
+    <TestComponent client={client}>
+      <Avatar
+        id={member.userId}
+        name={displayName}
+        size={96}
+        src={member?.getMxcAvatarUrl()}
+      />
+    </TestComponent>,
+  );
+  const element = screen.getByRole("img", { name: "@alice:example.org" });
+  expect(element.tagName).toEqual("SPAN");
+  expect(client.mxcUrlToHttp).toBeCalledTimes(0);
+});
+test("should attempt to fetch authenticated media", async () => {
+  const expectedAuthUrl = "http://example.org/media/alice-avatar";
+  const expectedObjectURL = "my-object-url";
+  const accessToken = "my-access-token";
+  const theBlob = new Blob([]);
+
+  // vitest doesn't have a implementation of create/revokeObjectURL, so we need
+  // to delete the property. It's a bit odd, but it works.
+  Reflect.deleteProperty(global.window.URL, "createObjectURL");
+  globalThis.URL.createObjectURL = vi.fn().mockReturnValue(expectedObjectURL);
+  Reflect.deleteProperty(global.window.URL, "revokeObjectURL");
+  globalThis.URL.revokeObjectURL = vi.fn();
+
+  const fetchFn = vi.fn().mockResolvedValue({
+    blob: async () => Promise.resolve(theBlob),
+  });
+  vi.stubGlobal("fetch", fetchFn);
+
+  const client = vi.mocked<MatrixClient>({
+    getAccessToken: () => accessToken,
+    mxcUrlToHttp: () => vi.fn(),
+  } as unknown as MatrixClient);
+
+  vi.spyOn(client, "mxcUrlToHttp").mockReturnValue(expectedAuthUrl);
+  const member = mockMatrixRoomMember({
+    userId: "@alice:example.org",
+    getMxcAvatarUrl: () => "mxc://example.org/alice-avatar",
+  });
+  const displayName = "Alice";
+  render(
+    <TestComponent client={client}>
+      <Avatar
+        id={member.userId}
+        name={displayName}
+        size={96}
+        src={member?.getMxcAvatarUrl()}
+      />
+    </TestComponent>,
+  );
+
+  // Fetch is asynchronous, so wait for this to resolve.
+  await vi.waitUntil(() =>
+    document.querySelector(`img[src='${expectedObjectURL}']`),
+  );
+
+  expect(client.mxcUrlToHttp).toBeCalledTimes(1);
+  expect(globalThis.fetch).toBeCalledWith(expectedAuthUrl, {
+    headers: { Authorization: `Bearer ${accessToken}` },
+  });
+});
diff --git a/src/Avatar.tsx b/src/Avatar.tsx
index 84b0ed48..a68c17f8 100644
--- a/src/Avatar.tsx
+++ b/src/Avatar.tsx
@@ -100,12 +100,11 @@ export const Avatar: FC<Props> = ({
       },
     })
       .then(async (req) => req.blob())
-      .then((res) => {
-        objectUrl = URL.createObjectURL(res);
+      .then((blob) => {
+        objectUrl = URL.createObjectURL(blob);
         setAvatarUrl(objectUrl);
       })
-      .catch(() => {
-        // Error will likely be evident from browser logs.
+      .catch((ex) => {
         setAvatarUrl(undefined);
       });
 
diff --git a/src/ClientContext.tsx b/src/ClientContext.tsx
index 8b5589d5..07b78dad 100644
--- a/src/ClientContext.tsx
+++ b/src/ClientContext.tsx
@@ -71,6 +71,8 @@ export type SetClientParams = {
 
 const ClientContext = createContext<ClientState | undefined>(undefined);
 
+export const ClientContextProvider = ClientContext.Provider;
+
 export const useClientState = (): ClientState | undefined =>
   useContext(ClientContext);