diff --git a/src/runtime/export_futex_test.go b/src/runtime/export_futex_test.go
deleted file mode 100644
index 03157d8eed..0000000000
--- a/src/runtime/export_futex_test.go
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 2013 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build dragonfly || freebsd || linux
-
-package runtime
-
-var Futexwakeup = futexwakeup
-
-//go:nosplit
-func Futexsleep(addr *uint32, val uint32, ns int64) {
-	// Temporarily disable preemption so that a preemption signal
-	// doesn't interrupt the system call.
-	poff := debug.asyncpreemptoff
-	debug.asyncpreemptoff = 1
-	futexsleep(addr, val, ns)
-	debug.asyncpreemptoff = poff
-}
diff --git a/src/runtime/export_test.go b/src/runtime/export_test.go
index 3c8f9eb49b..0f21838721 100644
--- a/src/runtime/export_test.go
+++ b/src/runtime/export_test.go
@@ -1328,3 +1328,5 @@ func Acquirem() {
 func Releasem() {
 	releasem(getg().m)
 }
+
+var Timediv = timediv
diff --git a/src/runtime/futex_test.go b/src/runtime/futex_test.go
deleted file mode 100644
index 188d0c6525..0000000000
--- a/src/runtime/futex_test.go
+++ /dev/null
@@ -1,87 +0,0 @@
-// Copyright 2013 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Futex is only available on DragonFly BSD, FreeBSD and Linux.
-// The race detector emits calls to split stack functions so it breaks
-// the test.
-
-//go:build (dragonfly || freebsd || linux) && !race
-
-package runtime_test
-
-import (
-	"runtime"
-	"sync"
-	"sync/atomic"
-	"testing"
-	"time"
-)
-
-type futexsleepTest struct {
-	mtx uint32
-	ns  int64
-	msg string
-	ch  chan *futexsleepTest
-}
-
-var futexsleepTests = []futexsleepTest{
-	beforeY2038: {mtx: 0, ns: 86400 * 1e9, msg: "before the year 2038"},
-	afterY2038:  {mtx: 0, ns: (1<<31 + 100) * 1e9, msg: "after the year 2038"},
-}
-
-const (
-	beforeY2038 = iota
-	afterY2038
-)
-
-func TestFutexsleep(t *testing.T) {
-	if runtime.GOMAXPROCS(0) > 1 {
-		// futexsleep doesn't handle EINTR or other signals,
-		// so spurious wakeups may happen.
-		t.Skip("skipping; GOMAXPROCS>1")
-	}
-
-	start := time.Now()
-	var wg sync.WaitGroup
-	for i := range futexsleepTests {
-		tt := &futexsleepTests[i]
-		tt.mtx = 0
-		tt.ch = make(chan *futexsleepTest, 1)
-		wg.Add(1)
-		go func(tt *futexsleepTest) {
-			runtime.Entersyscall()
-			runtime.Futexsleep(&tt.mtx, 0, tt.ns)
-			runtime.Exitsyscall()
-			tt.ch <- tt
-			wg.Done()
-		}(tt)
-	}
-loop:
-	for {
-		select {
-		case tt := <-futexsleepTests[beforeY2038].ch:
-			t.Errorf("futexsleep test %q finished early after %s", tt.msg, time.Since(start))
-			break loop
-		case tt := <-futexsleepTests[afterY2038].ch:
-			// Looks like FreeBSD 10 kernel has changed
-			// the semantics of timedwait on userspace
-			// mutex to make broken stuff look broken.
-			switch {
-			case runtime.GOOS == "freebsd" && runtime.GOARCH == "386":
-				t.Log("freebsd/386 may not work correctly after the year 2038, see golang.org/issue/7194")
-			default:
-				t.Errorf("futexsleep test %q finished early after %s", tt.msg, time.Since(start))
-				break loop
-			}
-		case <-time.After(time.Second):
-			break loop
-		}
-	}
-	for i := range futexsleepTests {
-		tt := &futexsleepTests[i]
-		atomic.StoreUint32(&tt.mtx, 1)
-		runtime.Futexwakeup(&tt.mtx, 1)
-	}
-	wg.Wait()
-}
diff --git a/src/runtime/runtime_test.go b/src/runtime/runtime_test.go
index 1ca1fa2f05..12f261bdd2 100644
--- a/src/runtime/runtime_test.go
+++ b/src/runtime/runtime_test.go
@@ -6,6 +6,7 @@ package runtime_test
 
 import (
 	"flag"
+	"fmt"
 	"io"
 	. "runtime"
 	"runtime/debug"
@@ -362,3 +363,78 @@ func TestVersion(t *testing.T) {
 		t.Fatalf("cr/nl in version: %q", vers)
 	}
 }
+
+func TestTimediv(t *testing.T) {
+	for _, tc := range []struct {
+		num int64
+		div int32
+		ret int32
+		rem int32
+	}{
+		{
+			num: 8,
+			div: 2,
+			ret: 4,
+			rem: 0,
+		},
+		{
+			num: 9,
+			div: 2,
+			ret: 4,
+			rem: 1,
+		},
+		{
+			// Used by runtime.check.
+			num: 12345*1000000000 + 54321,
+			div: 1000000000,
+			ret: 12345,
+			rem: 54321,
+		},
+		{
+			num: 1<<32 - 1,
+			div: 2,
+			ret: 1<<31 - 1, // no overflow.
+			rem: 1,
+		},
+		{
+			num: 1 << 32,
+			div: 2,
+			ret: 1<<31 - 1, // overflow.
+			rem: 0,
+		},
+		{
+			num: 1 << 40,
+			div: 2,
+			ret: 1<<31 - 1, // overflow.
+			rem: 0,
+		},
+		{
+			num: 1<<40 + 1,
+			div: 1 << 10,
+			ret: 1 << 30,
+			rem: 1,
+		},
+	} {
+		name := fmt.Sprintf("%d div %d", tc.num, tc.div)
+		t.Run(name, func(t *testing.T) {
+			// Double check that the inputs make sense using
+			// standard 64-bit division.
+			ret64 := tc.num / int64(tc.div)
+			rem64 := tc.num % int64(tc.div)
+			if ret64 != int64(int32(ret64)) {
+				// Simulate timediv overflow value.
+				ret64 = 1<<31 - 1
+				rem64 = 0
+			}
+			if ret64 != int64(tc.ret) {
+				t.Errorf("%d / %d got ret %d rem %d want ret %d rem %d", tc.num, tc.div, ret64, rem64, tc.ret, tc.rem)
+			}
+
+			var rem int32
+			ret := Timediv(tc.num, tc.div, &rem)
+			if ret != tc.ret || rem != tc.rem {
+				t.Errorf("timediv %d / %d got ret %d rem %d want ret %d rem %d", tc.num, tc.div, ret, rem, tc.ret, tc.rem)
+			}
+		})
+	}
+}