--- japron/gmp/gmp_Mpfr.c.orig	2013-07-05 16:16:16.000000000 -0600
+++ japron/gmp/gmp_Mpfr.c	2019-07-17 16:02:33.642733801 -0600
@@ -824,10 +824,23 @@ JNIEXPORT jint JNICALL Java_gmp_Mpfr_cbr
 JNIEXPORT jint JNICALL Java_gmp_Mpfr_root
   (JNIEnv *env, jobject o1, jobject o2, jint i, jint p)
 {
+#if MPFR_VERSION_MAJOR >= 4
+  mpfr_ptr mpfr1, mpfr2;
+#endif
   check_nonnull(o1,0);
   check_nonnull(o2,0);
   check_positive(i,0);
+#if MPFR_VERSION_MAJOR >= 4
+  mpfr1 = as_mpfr(o1);
+  mpfr2 = as_mpfr(o2);
+  if (mpfr_zero_p(mpfr2)) {
+    mpfr_set_zero(mpfr1, mpfr_sgn(mpfr2));
+    return 0;
+  }
+  return mpfr_rootn_ui(mpfr1, mpfr2, i, p);
+#else
   return mpfr_root(as_mpfr(o1), as_mpfr(o2), i, p);
+#endif
 }
 
 /*
--- num/numflt_mpfr.h.orig	2015-12-11 02:59:58.000000000 -0700
+++ num/numflt_mpfr.h	2019-07-17 16:04:45.307464218 -0600
@@ -123,8 +123,18 @@ static inline void numflt_root(numflt_t
 {
   assert(n > 0);
   assert((n & 1) || (mpfr_sgn(b) >= 0));
+#if MPFR_VERSION_MAJOR >= 4
+  if (mpfr_zero_p(b)) {
+    mpfr_set_zero(up, mpfr_sgn(b));
+    mpfr_set_zero(down, mpfr_sgn(b));
+  } else {
+    mpfr_rootn_ui(up, b, n, GMP_RNDU);
+    mpfr_rootn_ui(down, b, n, GMP_RNDD);
+  }
+#else
   mpfr_root(up, b, n, GMP_RNDU);
   mpfr_root(down, b, n, GMP_RNDD);
+#endif
 }
 static inline void numflt_mul_2exp(numflt_t a, numflt_t b, int c)
 { mpfr_mul_2si(a,b,c,GMP_RNDU); }
--- num/numflt_native.h.orig	2015-05-18 08:17:02.000000000 -0600
+++ num/numflt_native.h	2019-07-17 16:04:02.792197087 -0600
@@ -188,18 +188,46 @@ static inline void numflt_root(numflt_t
 #if defined(NUMFLT_DOUBLE)
   mpfr_init_set_d(arg, *b, GMP_RNDU);
   mpfr_init(res);
+#if MPFR_VERSION_MAJOR >= 4
+  if (mpfr_zero_p(arg))
+    mpfr_set_zero(res, mpfr_sgn(arg));
+  else
+    mpfr_rootn_ui(res, arg, n, GMP_RNDU);
+#else
   mpfr_root(res, arg, n, GMP_RNDU);
+#endif
   *up = mpfr_get_d(res, GMP_RNDU);
   mpfr_set_d(arg, *b, GMP_RNDD);
+#if MPFR_VERSION_MAJOR >= 4
+  if (mpfr_zero_p(arg))
+    mpfr_set_zero(res, mpfr_sgn(arg));
+  else
+    mpfr_rootn_ui(res, arg, n, GMP_RNDD);
+#else
   mpfr_root(res, arg, n, GMP_RNDD);
+#endif
   *down = mpfr_get_d(res, GMP_RNDD);
 #else
   mpfr_init_set_ld(arg, *b, GMP_RNDU);
   mpfr_init(res);
+#if MPFR_VERSION_MAJOR >= 4
+  if (mpfr_zero_p(arg))
+    mpfr_set_zero(res, mpfr_sgn(arg));
+  else
+    mpfr_rootn_ui(res, arg, n, GMP_RNDU);
+#else
   mpfr_root(res, arg, n, GMP_RNDU);
+#endif
   *up = mpfr_get_ld(res, GMP_RNDU);
   mpfr_set_ld(arg, *b, GMP_RNDD);
+#if MPFR_VERSION_MAJOR >= 4
+  if (mpfr_zero_p(arg))
+    mpfr_set_zero(res, mpfr_sgn(arg));
+  else
+    mpfr_rootn_ui(res, arg, n, GMP_RNDD);
+#else
   mpfr_root(res, arg, n, GMP_RNDD);
+#endif
   *down = mpfr_get_ld(res, GMP_RNDD);
 #endif
   mpfr_clear(arg);