diff --git a/ts/components/session/conversation/SessionCompositionBox.tsx b/ts/components/session/conversation/SessionCompositionBox.tsx
index dab9060fa..0d48e0b8f 100644
--- a/ts/components/session/conversation/SessionCompositionBox.tsx
+++ b/ts/components/session/conversation/SessionCompositionBox.tsx
@@ -796,8 +796,8 @@ class SessionCompositionBoxInner extends React.Component<Props, State> {
   }
 
   private async onKeyDown(event: any) {
-    if (event.key === 'Enter' && !event.shiftKey) {
-      // If shift, newline. Else send message.
+    if (event.key === 'Enter' && !event.shiftKey && !event.nativeEvent.isComposing) {
+      // If shift, newline. If in IME composing mode, leave it to IME. Else send message.
       event.preventDefault();
       await this.onSendMessage();
     } else if (event.key === 'Escape' && this.state.showEmojiPanel) {