merge
diff --git a/Modules/_decimal/libmpdec/mpdecimal.c b/Modules/_decimal/libmpdec/mpdecimal.c
index d6937bd..52df947 100644
--- a/Modules/_decimal/libmpdec/mpdecimal.c
+++ b/Modules/_decimal/libmpdec/mpdecimal.c
@@ -3530,6 +3530,7 @@
         MPD_NEW_STATIC(r,0,0,0,0);
         _mpd_base_ndivmod(q, &r, a, b, status);
         if (mpd_isspecial(q) || mpd_isspecial(&r)) {
+            mpd_setspecial(q, MPD_POS, MPD_NAN);
             mpd_del(&r);
             goto finish;
         }