diff --git a/apps/mobile/src/features/threads/threadAgentsPresentation.test.ts b/apps/mobile/src/features/threads/threadAgentsPresentation.test.ts
index 171d73a148597..e0771be61c5eb 100644
--- a/apps/mobile/src/features/threads/threadAgentsPresentation.test.ts
+++ b/apps/mobile/src/features/threads/threadAgentsPresentation.test.ts
@@ -64,10 +64,15 @@ describe("resolveSubagentRowPresentation", () => {
 
   it("falls back to a trimmed prompt when the agent has no title", () => {
     const long = resolveSubagentRowPresentation({ ...base, prompt: "x".repeat(200) });
+    const emoji = resolveSubagentRowPresentation({
+      ...base,
+      prompt: `${"x".repeat(76)}😀 and more`,
+    });
     const titled = resolveSubagentRowPresentation({ ...base, title: "Subagent: /root/my_worker" });
 
     expect(long.title).toHaveLength(80);
     expect(long.title.endsWith("...")).toBe(true);
+    expect(emoji.title).toBe(`${"x".repeat(76)}...`);
     expect(titled.title).toBe("My Worker");
   });
 
diff --git a/apps/mobile/src/features/threads/threadAgentsPresentation.ts b/apps/mobile/src/features/threads/threadAgentsPresentation.ts
index 7f560497da254..1e0f0c7960592 100644
--- a/apps/mobile/src/features/threads/threadAgentsPresentation.ts
+++ b/apps/mobile/src/features/threads/threadAgentsPresentation.ts
@@ -58,9 +58,14 @@ function rowTitle(subagent: Pick<OrchestrationV2Subagent, "title" | "prompt">):
   if (title) return formatSubagentDisplayTitle(title);
   const prompt = subagent.prompt.trim();
   if (prompt.length === 0) return "Subagent";
-  return prompt.length > PROMPT_TITLE_LIMIT
-    ? `${prompt.slice(0, PROMPT_TITLE_LIMIT - 3)}...`
-    : prompt;
+  if (prompt.length <= PROMPT_TITLE_LIMIT) return prompt;
+  let end = PROMPT_TITLE_LIMIT - 3;
+  const previous = prompt.charCodeAt(end - 1);
+  const next = prompt.charCodeAt(end);
+  if (previous >= 0xd800 && previous <= 0xdbff && next >= 0xdc00 && next <= 0xdfff) {
+    end -= 1;
+  }
+  return `${prompt.slice(0, end)}...`;
 }
 
 function rowTone(status: OrchestrationV2Subagent["status"]): SubagentRowTone {