diff --git a/acb_dft.h b/acb_dft.h
index cc681778..01f5ddaa 100644
--- a/acb_dft.h
+++ b/acb_dft.h
@@ -246,7 +246,7 @@ acb_dft_rad2_init(acb_dft_rad2_t t, int e, slong prec)
 ACB_DFT_INLINE void
 acb_dft_rad2_clear(acb_dft_rad2_t t)
 {
-    _acb_vec_clear(t->z, t->n);
+    _acb_vec_clear(t->z, t->nz);
 }
 
 void _acb_dft_bluestein_init(acb_dft_bluestein_t t, slong dv, slong n, slong prec);
diff --git a/acb_dft/bluestein.c b/acb_dft/bluestein.c
index 04052d2d..71197919 100644
--- a/acb_dft/bluestein.c
+++ b/acb_dft/bluestein.c
@@ -26,7 +26,7 @@ _acb_vec_bluestein_factors(acb_ptr z, slong n, slong prec)
         nmod_t n2;
 
         z2n = _acb_vec_init(2 * n);
-        _acb_vec_unit_roots(z2n, 2 * n, prec);
+        _acb_vec_unit_roots(z2n, 2 * n, -2 * n, prec);
         nmod_init(&n2, 2 * n);
 
         for (k = 0, k2 = 0; k < n; k++)
@@ -65,6 +65,7 @@ _acb_vec_bluestein_factors(acb_ptr z, slong n, slong prec)
 
         acb_one(t + 0);
         acb_unit_root(t + 1, 2 * n, prec);
+        acb_conj(t + 1, t + 1);
         acb_set_si(t + n, -1);
         for (k = 2; k < n; k++)
             if (v[k])
diff --git a/acb_dft/cyc.c b/acb_dft/cyc.c
index 2e922fa3..3195f218 100644
--- a/acb_dft/cyc.c
+++ b/acb_dft/cyc.c
@@ -27,7 +27,7 @@ _acb_dft_cyc_init_z_fac(acb_dft_cyc_t t, n_factor_t fac, slong dv, acb_ptr z, sl
         if (DFT_VERB)
             flint_printf("dft_cyc: init z[%wu]\n", t->n);
         z = _acb_vec_init(t->n);
-        _acb_vec_unit_roots(z, t->n, prec);
+        _acb_vec_unit_roots(z, t->n, -t->n, prec);
         dz = 1;
         t->zclear = 1;
     }
diff --git a/acb_dft/naive.c b/acb_dft/naive.c
index fba1e4f1..9dabe1a6 100644
--- a/acb_dft/naive.c
+++ b/acb_dft/naive.c
@@ -57,7 +57,7 @@ acb_dft_naive(acb_ptr w, acb_srcptr v, slong len, slong prec)
     acb_ptr z, v1 = NULL;
 
     z = _acb_vec_init(len);
-    _acb_vec_unit_roots(z, len, prec);
+    _acb_vec_unit_roots(z, len, -len, prec);
     if (w == v)
     {
         v1 = _acb_vec_init(len);
@@ -84,7 +84,7 @@ _acb_dft_naive_init(acb_dft_naive_t pol, slong dv, acb_ptr z, slong dz, slong le
         if (DFT_VERB)
             flint_printf("dft_naive: init z[%ld]\n",len);
         pol->z = _acb_vec_init(len);
-        _acb_vec_unit_roots(pol->z, len, prec);
+        _acb_vec_unit_roots(pol->z, len, -len, prec);
         pol->dz = 1;
         pol->zclear = 1;
     }
diff --git a/acb_dft/rad2.c b/acb_dft/rad2.c
index d8883d37..767c7a65 100644
--- a/acb_dft/rad2.c
+++ b/acb_dft/rad2.c
@@ -43,10 +43,9 @@ _acb_dft_rad2_init(acb_dft_rad2_t t, slong dv, int e, slong prec)
     t->n = 1 << e;
     t->dv = dv;
     t->nz = t->n >> 1;
-    t->z = _acb_vec_init(t->n);
+    t->z = _acb_vec_init(t->nz);
     /* set n/2 roots of order n */
-    /* xxx: don't compute twice the number */
-    _acb_vec_unit_roots(t->z, t->n, prec);
+    _acb_vec_unit_roots(t->z, t->nz, -t->n, prec);
 }
 
 /* remark: can use same rad2 with smaller power of 2 */
diff --git a/acb_dft/test/t-convol.c b/acb_dft/test/t-convol.c
index e05278ba..e81bae4e 100644
--- a/acb_dft/test/t-convol.c
+++ b/acb_dft/test/t-convol.c
@@ -86,8 +86,13 @@ int main()
 
         for (i = 0; i < len; i++)
         {
-            acb_set_si(x + i, n_randint(state, len));
-            acb_set_si(y + i, n_randint(state, len));
+#if 1
+            acb_set_si(x + i, n_randint(state, 4 * len));
+            acb_set_si(y + i, n_randint(state, 4 * len));
+#else
+            acb_set_si_si(x + i, n_randint(state, 4 * len), n_randint(state, 4 * len));
+            acb_set_si_si(y + i, n_randint(state, 4 * len), n_randint(state, 4 * len));
+#endif
         }
 
         for (f = 0; f < nf; f++)
@@ -115,5 +120,3 @@ int main()
     flint_printf("PASS\n");
     return EXIT_SUCCESS;
 }
-
-
diff --git a/acb_dft/test/t-dft.c b/acb_dft/test/t-dft.c
index c5a4e1f5..0afe29fb 100644
--- a/acb_dft/test/t-dft.c
+++ b/acb_dft/test/t-dft.c
@@ -133,7 +133,7 @@ int main()
         w1 = _acb_vec_init(n);
 
         for (j = 0; j < n; j++)
-            acb_set_si(v + k, k);
+            acb_set_si_si(v + j, j, j + 2);
 
         acb_dft_naive(w1, v, n, prec);
         acb_dft_rad2_inplace(w2, k, prec);