diff --git a/src/math/nextafter.c b/src/math/nextafter.c
index 76e0db4..344cc54 100644
--- a/src/math/nextafter.c
+++ b/src/math/nextafter.c
@@ -79,13 +79,3 @@ void bench_nextafter_subnormal(int N)
 		z = nextafter(0x1p-1070, -0x1p-1071);
 	}
 }
-
-void bench_nextafter_zero(int N)
-{
-	int i;
-	volatile double z;
-
-	for (i = 0; i < N; i++) {
-		z = nextafter(0, -0x1p-1071);
-	}
-}
diff --git a/src/math/nextafterl.c b/src/math/nextafterl.c
new file mode 100644
index 0000000..9aa9421
--- /dev/null
+++ b/src/math/nextafterl.c
@@ -0,0 +1,88 @@
+#include <math.h>
+#include <stdint.h>
+#include <fenv.h>
+#include <stdio.h>
+#include <float.h>
+#include <stdlib.h>
+#include "fenvutil.h"
+#include "test.h"
+
+/* ld80 only */
+
+static struct {
+	long double x;
+	long double y;
+	long double z;
+	int except;
+} t[] = {
+           0,         0,                            0, 0,
+           0,      -0.0,                         -0.0, 0,
+        -0.0,         0,                            0, 0,
+           0,         1,                  0x1p-16445L, FE_INEXACT|FE_UNDERFLOW,
+           0,        -1,                 -0x1p-16445L, FE_INEXACT|FE_UNDERFLOW,
+        -0.0,         1,                  0x1p-16445L, FE_INEXACT|FE_UNDERFLOW,
+        -0.0,        -1,                 -0x1p-16445L, FE_INEXACT|FE_UNDERFLOW,
+ 0x1p-16445L,  INFINITY,                  0x1p-16444L, FE_INEXACT|FE_UNDERFLOW,
+ 0x1p-16445L, -INFINITY,                            0, FE_INEXACT|FE_UNDERFLOW,
+-0x1p-16445L,  INFINITY,                         -0.0, FE_INEXACT|FE_UNDERFLOW,
+-0x1p-16445L, -INFINITY,                 -0x1p-16444L, FE_INEXACT|FE_UNDERFLOW,
+ 0x1p-16440L, -0x1p-16444L,             0x1.fp-16441L, FE_INEXACT|FE_UNDERFLOW,
+ 0x1p-16440L,  0x1p-16444L,             0x1.fp-16441L, FE_INEXACT|FE_UNDERFLOW,
+ 0x1p-16440L,  0x1p-16430L,            0x1.08p-16440L, FE_INEXACT|FE_UNDERFLOW,
+    LDBL_MIN,         0, 0x1.fffffffffffffffcp-16383L, FE_INEXACT|FE_UNDERFLOW,
+   -LDBL_MIN,         0,-0x1.fffffffffffffffcp-16383L, FE_INEXACT|FE_UNDERFLOW,
+ 0x1.fffffffffffffffcp-16383L,  1,           LDBL_MIN, 0,
+-0x1.fffffffffffffffcp-16383L, -1,          -LDBL_MIN, 0,
+           1,         2,     0x1.0000000000000002p+0L, 0,
+           1,        -2,     0x1.fffffffffffffffep-1L, 0,
+           1,       0.5,     0x1.fffffffffffffffep-1L, 0,
+    0x1p1023,  0x1p1000,  0x1.fffffffffffffffep+1022L, 0,
+    0x1p1023,  INFINITY,  0x1.0000000000000002p+1023L, 0,
+        -1.5,      -2.5,    -0x1.8000000000000002p+0L, 0,
+        -1.5,       2.5,    -0x1.7ffffffffffffffep+0L, 0,
+         1.5,      -2.5,     0x1.7ffffffffffffffep+0L, 0,
+    LDBL_MAX,  INFINITY,                     INFINITY, FE_INEXACT|FE_OVERFLOW,
+    INFINITY,  INFINITY,                     INFINITY, 0,
+   -LDBL_MAX, -INFINITY,                    -INFINITY, FE_INEXACT|FE_OVERFLOW,
+   -INFINITY, -INFINITY,                    -INFINITY, 0,
+         NAN,         1,                          NAN, 0,
+           1,       NAN,                          NAN, 0,
+};
+
+void test_nextafterl()
+{
+	int f, i;
+	long double z;
+
+	for (i = 0; i < sizeof t/sizeof *t; i++) {
+		feclearexcept(FE_ALL_EXCEPT);
+		z = nextafterl(t[i].x, t[i].y);
+		f = fetestexcept(FE_INVALID|FE_DIVBYZERO|FE_OVERFLOW|FE_UNDERFLOW|FE_INEXACT);
+
+		if (z != t[i].z && !(isnan(z) && isnan(t[i].z)))
+			error("%d nextafterl(%La, %La) want %La got %La\n", i, t[i].x, t[i].y, t[i].z, z);
+		if (f != t[i].except)
+			error("%d nextafterl(%La, %La)==%La want except=%s got except=%s\n",
+				i, t[i].x, t[i].y, t[i].z, strdup(strexcept(t[i].except)), strdup(strexcept(f)));
+	}
+}
+
+void bench_nextafterl_normal(int N)
+{
+	int i;
+	volatile long double z;
+
+	for (i = 0; i < N; i++) {
+		z = nextafterl(1.25, 4);
+	}
+}
+
+void bench_nextafterl_subnormal(int N)
+{
+	int i;
+	volatile long double z;
+
+	for (i = 0; i < N; i++) {
+		z = nextafterl(0x1p-16440L, -0x1p-16444L);
+	}
+}