diff --git a/acb_elliptic/e_inc.c b/acb_elliptic/e_inc.c
index d01deda1..5935e6ee 100644
--- a/acb_elliptic/e_inc.c
+++ b/acb_elliptic/e_inc.c
@@ -142,7 +142,7 @@ acb_elliptic_e_inc(acb_t res, const acb_t phi, const acb_t m, int times_pi, slon
         acb_zero(z);
         arf_set_mag(arb_midref(acb_realref(z)), arb_radref(d));
         mag_zero(arb_radref(d));
-        arb_sub(d, d, acb_realref(z), prec);
+        arb_sub(d, d, acb_realref(z), 2 * prec + 100); /* meant to be exact */
         arb_floor(d, d, prec);
 
         /* w = 2 E(m) */
diff --git a/acb_elliptic/f.c b/acb_elliptic/f.c
index 34afd8d7..bf9b6e24 100644
--- a/acb_elliptic/f.c
+++ b/acb_elliptic/f.c
@@ -127,7 +127,7 @@ acb_elliptic_f(acb_t res, const acb_t phi, const acb_t m, int times_pi, slong pr
         acb_zero(z);
         arf_set_mag(arb_midref(acb_realref(z)), arb_radref(d));
         mag_zero(arb_radref(d));
-        arb_sub(d, d, acb_realref(z), prec);
+        arb_sub(d, d, acb_realref(z), 2 * prec + 100); /* meant to be exact */
         arb_floor(d, d, prec);
 
         /* w = 2 K(m) */
diff --git a/acb_elliptic/pi.c b/acb_elliptic/pi.c
index 96144e77..4ecf45dd 100644
--- a/acb_elliptic/pi.c
+++ b/acb_elliptic/pi.c
@@ -182,7 +182,7 @@ acb_elliptic_pi_inc(acb_t res, const acb_t n, const acb_t phi, const acb_t m, in
         acb_zero(z);
         arf_set_mag(arb_midref(acb_realref(z)), arb_radref(d));
         mag_zero(arb_radref(d));
-        arb_sub(d, d, acb_realref(z), prec);
+        arb_sub(d, d, acb_realref(z), 2 * prec + 100); /* meant to be exact */
         arb_floor(d, d, prec);
 
         /* w = 2 Pi(n, m) */