diff --git a/packages/frontend/src/components/MkSignin.vue b/packages/frontend/src/components/MkSignin.vue
index 76a6537ccc..2ac5c41964 100644
--- a/packages/frontend/src/components/MkSignin.vue
+++ b/packages/frontend/src/components/MkSignin.vue
@@ -107,14 +107,17 @@ const props = withDefaults(defineProps<{
 });
 
 function onUsernameChange(): void {
+	const usernameRequested = username.value;
 	misskeyApi('users/show', {
-		username: username.value,
+		username: usernameRequested,
 	}).then(userResponse => {
 		if (userResponse.username === username.value) {
 			user.value = userResponse;
 		}
 	}, () => {
-		user.value = null;
+		if (usernameRequested === username.value) {
+			user.value = null;
+		}
 	});
 }