diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4a1404b96..934cb4cbd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -40,6 +40,7 @@
 - System prompt now tags allowlisted owner numbers as the user identity to avoid mistaken “friend” assumptions.
 - LM Studio/Ollama replies now require <final> tags; streaming ignores content until <final> begins.
 - LM Studio responses API: tools payloads no longer include `strict: null`, and LM Studio no longer gets forced `<think>/<final>` tags.
+- Empty `messages.responsePrefix` now disables the identity emoji prefix.
 - `process log` pagination is now line-based (omit `offset` to grab the last N lines).
 - macOS WebChat: assistant bubbles now update correctly when toggling light/dark mode.
 - macOS: avoid spawning a duplicate gateway process when an external listener already exists.
diff --git a/src/config/config.test.ts b/src/config/config.test.ts
index a94ff0c6d..f5b6fd2fe 100644
--- a/src/config/config.test.ts
+++ b/src/config/config.test.ts
@@ -91,6 +91,32 @@ describe("config identity defaults", () => {
     });
   });
 
+  it("respects empty responsePrefix to disable identity defaults", async () => {
+    await withTempHome(async (home) => {
+      const configDir = path.join(home, ".clawdis");
+      await fs.mkdir(configDir, { recursive: true });
+      await fs.writeFile(
+        path.join(configDir, "clawdis.json"),
+        JSON.stringify(
+          {
+            identity: { name: "Samantha", theme: "helpful sloth", emoji: "🦥" },
+            messages: { responsePrefix: "" },
+            routing: {},
+          },
+          null,
+          2,
+        ),
+        "utf-8",
+      );
+
+      vi.resetModules();
+      const { loadConfig } = await import("./config.js");
+      const cfg = loadConfig();
+
+      expect(cfg.messages?.responsePrefix).toBe("");
+    });
+  });
+
   it("does not synthesize agent/session when absent", async () => {
     await withTempHome(async (home) => {
       const configDir = path.join(home, ".clawdis");
diff --git a/src/config/config.ts b/src/config/config.ts
index b2a79a0d5..5e4363af9 100644
--- a/src/config/config.ts
+++ b/src/config/config.ts
@@ -878,7 +878,7 @@ function applyIdentityDefaults(cfg: ClawdisConfig): ClawdisConfig {
   let mutated = false;
   const next: ClawdisConfig = { ...cfg };
 
-  if (emoji && !messages.responsePrefix) {
+  if (emoji && messages.responsePrefix === undefined) {
     next.messages = { ...(next.messages ?? messages), responsePrefix: emoji };
     mutated = true;
   }