diff --git a/desktop/src/features/messages/ui/MessageReactions.tsx b/desktop/src/features/messages/ui/MessageReactions.tsx
index 2250b3931f..cbcb873f5b 100644
--- a/desktop/src/features/messages/ui/MessageReactions.tsx
+++ b/desktop/src/features/messages/ui/MessageReactions.tsx
@@ -126,7 +126,10 @@ function ReactionPopoverContent({ reaction }: { reaction: TimelineReaction }) {
       <div className="max-w-[14rem] text-balance text-sm font-semibold leading-snug text-popover-foreground">
         {userText} <span className="text-muted-foreground">reacted with</span>
       </div>
-      <div className="mt-0.5 text-sm font-semibold leading-snug text-muted-foreground">
+      <div
+        className="mt-0.5 break-all text-sm font-semibold leading-snug text-muted-foreground"
+        data-testid="reaction-popover-name"
+      >
         {displayName}
       </div>
     </div>
@@ -504,7 +507,7 @@ function ReactionPill({
         align="start"
         side="top"
         sideOffset={6}
-        className="w-auto min-w-56 max-w-72 rounded-xl p-3"
+        className="w-72 rounded-xl p-3"
         onMouseEnter={handleMouseEnter}
         onMouseLeave={scheduleClose}
         onOpenAutoFocus={(e) => e.preventDefault()}
diff --git a/desktop/tests/e2e/fixtures/reaction-popover/bob-avatar.jpg b/desktop/tests/e2e/fixtures/reaction-popover/bob-avatar.jpg
new file mode 100644
index 0000000000..a63c5f0af5
Binary files /dev/null and b/desktop/tests/e2e/fixtures/reaction-popover/bob-avatar.jpg differ
diff --git a/desktop/tests/e2e/fixtures/reaction-popover/teammate-alice.jpg b/desktop/tests/e2e/fixtures/reaction-popover/teammate-alice.jpg
new file mode 100644
index 0000000000..55bc501448
Binary files /dev/null and b/desktop/tests/e2e/fixtures/reaction-popover/teammate-alice.jpg differ
diff --git a/desktop/tests/e2e/reaction-names.spec.ts b/desktop/tests/e2e/reaction-names.spec.ts
index 512b913dff..8d9a1d97d1 100644
--- a/desktop/tests/e2e/reaction-names.spec.ts
+++ b/desktop/tests/e2e/reaction-names.spec.ts
@@ -1,11 +1,41 @@
 import { expect, test } from "@playwright/test";
+import * as fs from "node:fs";
+import * as path from "node:path";
+import { fileURLToPath } from "node:url";
 
+import { waitForAnimations } from "../helpers/animations";
 import { installMockBridge } from "../helpers/bridge";
 
 const REACTION_TARGET_CONTENT = "React to me with a custom emoji";
 const REACTION_TARGET_EVENT_ID = "d".repeat(64);
 const BOB_PUBKEY =
   "bb22a5299220cad76ffd46190ccbeede8ab5dc260faa28b6e5a2cb31b9aff260";
+const MAX_REACTION_NAME =
+  "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijkl";
+const MAX_REACTION_AVATAR_URL =
+  "https://cdn.example.test/avatars/teammate-alice.jpg";
+const SHORT_REACTION_AVATAR_URL =
+  "https://cdn.example.test/avatars/bob-avatar.jpg";
+const AVATAR_FIXTURES = new Map([
+  [
+    MAX_REACTION_AVATAR_URL,
+    fileURLToPath(
+      new URL(
+        "./fixtures/reaction-popover/teammate-alice.jpg",
+        import.meta.url,
+      ),
+    ),
+  ],
+  [
+    SHORT_REACTION_AVATAR_URL,
+    fileURLToPath(
+      new URL("./fixtures/reaction-popover/bob-avatar.jpg", import.meta.url),
+    ),
+  ],
+]);
+const SCREENSHOT_DIR =
+  process.env.REACTION_POPOVER_SCREENSHOT_DIR ??
+  "test-results/reaction-popover-screenshots";
 
 function reactionTargetRow(page: import("@playwright/test").Page) {
   return page
@@ -14,8 +44,56 @@ function reactionTargetRow(page: import("@playwright/test").Page) {
     .last();
 }
 
+async function waitForImage(
+  image: import("@playwright/test").Locator,
+): Promise<void> {
+  await expect(image).toBeVisible();
+  await expect
+    .poll(() =>
+      image.evaluate(
+        (element) =>
+          element instanceof HTMLImageElement &&
+          element.complete &&
+          element.naturalWidth > 0,
+      ),
+    )
+    .toBe(true);
+}
+
+async function capturePopover(
+  page: import("@playwright/test").Page,
+  popover: import("@playwright/test").Locator,
+  filename: string,
+): Promise<void> {
+  fs.mkdirSync(SCREENSHOT_DIR, { recursive: true });
+  await waitForAnimations(page);
+  await popover.screenshot({
+    animations: "disabled",
+    path: path.join(SCREENSHOT_DIR, filename),
+  });
+}
+
 test.beforeEach(async ({ page }) => {
-  await installMockBridge(page);
+  await page.route("https://cdn.example.test/avatars/**", async (route) => {
+    const fixturePath = AVATAR_FIXTURES.get(route.request().url());
+    if (!fixturePath) {
+      await route.abort("blockedbyclient");
+      return;
+    }
+    await route.fulfill({
+      body: fs.readFileSync(fixturePath),
+      contentType: "image/jpeg",
+    });
+  });
+  await installMockBridge(page, {
+    searchProfiles: [
+      {
+        pubkey: BOB_PUBKEY,
+        displayName: "bob",
+        avatarUrl: SHORT_REACTION_AVATAR_URL,
+      },
+    ],
+  });
 });
 
 test("reaction popover resolves a reactor with no authored message in the window", async ({
@@ -33,21 +111,87 @@ test("reaction popover resolves a reactor with no authored message in the window
   );
 
   await page.evaluate(
-    ({ pubkey, targetId }) => {
+    ({ pubkey, targetId, avatarUrl }) => {
       window.__BUZZ_E2E_EMIT_MOCK_MESSAGE__?.({
         channelName: "general",
-        content: "🎉",
-        extraTags: [["e", targetId]],
+        content: ":react:",
+        extraTags: [
+          ["e", targetId],
+          ["emoji", "react", avatarUrl],
+        ],
         kind: 7,
         pubkey,
       });
     },
-    { pubkey: BOB_PUBKEY, targetId: REACTION_TARGET_EVENT_ID },
+    {
+      avatarUrl: SHORT_REACTION_AVATAR_URL,
+      pubkey: BOB_PUBKEY,
+      targetId: REACTION_TARGET_EVENT_ID,
+    },
   );
 
   const row = reactionTargetRow(page);
-  const pill = row.getByRole("button", { name: "Toggle 🎉 reaction" });
+  const pill = row.getByRole("button", { name: "Toggle :react: reaction" });
   await expect(pill).toBeVisible();
   await pill.hover();
   await expect(page.getByText("bob reacted with")).toBeVisible();
+  const popover = page
+    .locator("[data-radix-popper-content-wrapper]")
+    .filter({ hasText: "bob reacted with" });
+  const avatar = popover.locator(`img[src="${SHORT_REACTION_AVATAR_URL}"]`);
+  await waitForImage(avatar);
+  await capturePopover(page, popover, "short-name-after.png");
+});
+
+test("maximum-length reaction name wraps inside a fixed-width popover", async ({
+  page,
+}) => {
+  await page.goto("/");
+  await page.getByTestId("channel-general").click();
+  await expect(page.getByTestId("chat-title")).toHaveText("general");
+  await page.waitForFunction(
+    () =>
+      window.__BUZZ_E2E_HAS_MOCK_LIVE_SUBSCRIPTION__?.({
+        channelName: "general",
+        kind: 7,
+      }) === true,
+  );
+
+  const reaction = `:${MAX_REACTION_NAME}:`;
+  await page.evaluate(
+    ({ content, targetId, avatarUrl }) => {
+      window.__BUZZ_E2E_EMIT_MOCK_MESSAGE__?.({
+        channelName: "general",
+        content,
+        extraTags: [
+          ["e", targetId],
+          ["emoji", content.slice(1, -1), avatarUrl],
+        ],
+        kind: 7,
+      });
+    },
+    {
+      avatarUrl: MAX_REACTION_AVATAR_URL,
+      content: reaction,
+      targetId: REACTION_TARGET_EVENT_ID,
+    },
+  );
+
+  const pill = reactionTargetRow(page).getByRole("button", {
+    name: `Toggle ${reaction} reaction`,
+  });
+  await expect(pill).toBeVisible();
+  await pill.focus();
+
+  const popover = page
+    .locator("[data-radix-popper-content-wrapper]")
+    .filter({ hasText: reaction });
+  await expect(popover).toBeVisible();
+  await expect(popover).toHaveCSS("width", "288px");
+  const reactionName = popover.getByTestId("reaction-popover-name");
+  await expect(reactionName).toHaveCSS("word-break", "break-all");
+  await expect(reactionName).toHaveText(reaction);
+  const avatar = popover.locator(`img[src="${MAX_REACTION_AVATAR_URL}"]`);
+  await waitForImage(avatar);
+  await capturePopover(page, popover, "max-length-after.png");
 });