1 files changed, 1 insertions, 0 deletions
diff --git a/div_ui.c b/div_ui.c
index 0979ff75d..edb54803c 100644
--- a/div_ui.c
+++ b/div_ui.c
@@ -89,6 +89,7 @@ mpfr_div_ui (mpfr_ptr y, mpfr_srcptr x, unsigned long int u, mp_rnd_t rnd_mode)
   tmp = TMP_ALLOC((yn + 1) * BYTES_PER_MP_LIMB);
 
   c = (mp_limb_t) u;
+  MPFR_ASSERTN(u == c);
   if (dif >= 0)
     c = mpn_divrem_1 (tmp, dif, xp, xn, c); /* used all the dividend */
   else /* dif < 0 i.e. xn > yn, don't use the (-dif) low limbs from x */