diff --git a/src/support/userinfo.C b/src/support/userinfo.C
index bbda73b0f7..bc40829dbf 100644
--- a/src/support/userinfo.C
+++ b/src/support/userinfo.C
@@ -41,7 +41,7 @@ string const user_name()
 	char name[UNLEN + 1];
 	DWORD size = UNLEN + 1;
 	if (!GetUserName(name, &size))
-		return _("Unknown user");
+		return lyx::to_utf8(_("Unknown user"));
 	return name;
 #else
 	struct passwd * pw(getpwuid(geteuid()));