diff --git a/packages/app/src/components/prompt-input.tsx b/packages/app/src/components/prompt-input.tsx
index f1ca3ee888b..2f85652a93e 100644
--- a/packages/app/src/components/prompt-input.tsx
+++ b/packages/app/src/components/prompt-input.tsx
@@ -364,6 +364,12 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
     if (!isFocused()) setStore("popover", null)
   })
 
+  // Safety: reset composing state on focus change to prevent stuck state
+  // This handles edge cases where compositionend event may not fire
+  createEffect(() => {
+    if (!isFocused()) setComposing(false)
+  })
+
   type AtOption = { type: "agent"; name: string; display: string } | { type: "file"; path: string; display: string }
 
   const agentList = createMemo(() =>
@@ -881,6 +887,14 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
       }
     }
 
+    // Handle Shift+Enter BEFORE IME check - Shift+Enter is never used for IME input
+    // and should always insert a newline regardless of composition state
+    if (event.key === "Enter" && event.shiftKey) {
+      addPart({ type: "text", content: "\n", start: 0, end: 0 })
+      event.preventDefault()
+      return
+    }
+
     if (event.key === "Enter" && isImeComposing(event)) {
       return
     }
@@ -944,11 +958,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
       return
     }
 
-    if (event.key === "Enter" && event.shiftKey) {
-      addPart({ type: "text", content: "\n", start: 0, end: 0 })
-      event.preventDefault()
-      return
-    }
+    // Note: Shift+Enter is handled earlier, before IME check
     if (event.key === "Enter" && !event.shiftKey) {
       handleSubmit(event)
     }