diff --git a/src/web/public/keyboard-accessory.js b/src/web/public/keyboard-accessory.js
index 80c9f25d..8a629dfe 100644
--- a/src/web/public/keyboard-accessory.js
+++ b/src/web/public/keyboard-accessory.js
@@ -1276,6 +1276,7 @@ const KeyboardAccessoryBar = {
     const send = () => {
       const text = textarea.value;
       if (!text || !this._sendComposedPrompt(sessionId, text)) return;
+      app._echoPassthroughSessions?.delete(sessionId);
       this._composerDrafts.delete(sessionId);
       this._syncComposerDraftIndicator();
       close({ preserveDraft: false });
diff --git a/test/mobile-prompt-composer.test.ts b/test/mobile-prompt-composer.test.ts
index 8a827c36..5b16d120 100644
--- a/test/mobile-prompt-composer.test.ts
+++ b/test/mobile-prompt-composer.test.ts
@@ -38,6 +38,7 @@ function loadComposer(sessionId = 'session-1') {
     _localEchoOverlay: localEcho,
     _flushedOffsets: new Map<string, number>(),
     _flushedTexts: new Map<string, string>(),
+    _echoPassthroughSessions: new Set<string>(),
     _predictiveEcho: { clearPredictions: vi.fn() },
     _sendInputAsync: vi.fn(),
     _uploadAndInsertImages: vi.fn(async () => ['/tmp/image-one.png']),
@@ -248,6 +249,19 @@ describe('mobile prompt composer', () => {
     expect(app._sendInputAsync).toHaveBeenLastCalledWith('session-1', '\r', { useMux: true });
   });
 
+  it('releases echo passthrough after a composed prompt is queued', () => {
+    const { app, bar, document } = loadComposer();
+    app._echoPassthroughSessions.add('session-1');
+    app._echoPassthroughSessions.add('session-2');
+    bar.composePrompt();
+    textarea(document).value = 'send from composer';
+
+    (document.querySelector('.paste-send') as HTMLButtonElement).click();
+
+    expect(app._echoPassthroughSessions.has('session-1')).toBe(false);
+    expect(app._echoPassthroughSessions.has('session-2')).toBe(true);
+  });
+
   it('preserves the draft and focuses xterm when Use terminal keyboard is chosen', () => {
     const { app, bar, document, localEcho, runTimers } = loadComposer();
     const composeButton = mountComposeButton(bar, document);