diff --git a/ncurses/widechar/lib_unget_wch.c b/ncurses/widechar/lib_unget_wch.c
index 4ea26b6..df82974 100644
--- a/ncurses/widechar/lib_unget_wch.c
+++ b/ncurses/widechar/lib_unget_wch.c
@@ -76,6 +76,8 @@ NCURSES_SP_NAME(unget_wch) (NCURSES_SP_DCLx const wchar_t wch)
 
     init_mb(state);
     length = _nc_wcrtomb(0, wch, &state);
+    if (length < MB_CUR_MAX)
+      length = MB_CUR_MAX;
 
     if (length != (size_t) (-1)
 	&& length != 0) {