diff --git a/misc/cgo/testsanitizers/msan5.go b/misc/cgo/testsanitizers/msan5.go
new file mode 100644
index 0000000000..f1479eb8a0
--- /dev/null
+++ b/misc/cgo/testsanitizers/msan5.go
@@ -0,0 +1,57 @@
+// Copyright 2016 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.
+
+package main
+
+// Using reflect to set a value was not seen by msan.
+
+/*
+#include <stdlib.h>
+
+extern void Go1(int*);
+extern void Go2(char*);
+
+// Use weak as a hack to permit defining a function even though we use export.
+void C1() __attribute__ ((weak));
+void C2() __attribute__ ((weak));
+
+void C1() {
+	int i;
+	Go1(&i);
+	if (i != 42) {
+		abort();
+	}
+}
+
+void C2() {
+	char a[2];
+	a[1] = 42;
+	Go2(a);
+	if (a[0] != 42) {
+		abort();
+	}
+}
+*/
+import "C"
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+//export Go1
+func Go1(p *C.int) {
+	reflect.ValueOf(p).Elem().Set(reflect.ValueOf(C.int(42)))
+}
+
+//export Go2
+func Go2(p *C.char) {
+	a := (*[2]byte)(unsafe.Pointer(p))
+	reflect.Copy(reflect.ValueOf(a[:1]), reflect.ValueOf(a[1:]))
+}
+
+func main() {
+	C.C1()
+	C.C2()
+}
diff --git a/misc/cgo/testsanitizers/test.bash b/misc/cgo/testsanitizers/test.bash
index 78747d141a..6e6347ce29 100755
--- a/misc/cgo/testsanitizers/test.bash
+++ b/misc/cgo/testsanitizers/test.bash
@@ -88,6 +88,11 @@ if test "$msan" = "yes"; then
 	status=1
     fi
 
+    if ! go run -msan msan5.go; then
+	echo "FAIL: msan5"
+	status=1
+    fi
+
     if go run -msan msan_fail.go 2>/dev/null; then
 	echo "FAIL: msan_fail"
 	status=1
diff --git a/src/runtime/mbarrier.go b/src/runtime/mbarrier.go
index 4a8f501dfe..ac00fc6a9e 100644
--- a/src/runtime/mbarrier.go
+++ b/src/runtime/mbarrier.go
@@ -185,6 +185,14 @@ func typedmemmove(typ *_type, dst, src unsafe.Pointer) {
 
 //go:linkname reflect_typedmemmove reflect.typedmemmove
 func reflect_typedmemmove(typ *_type, dst, src unsafe.Pointer) {
+	if raceenabled {
+		raceWriteObjectPC(typ, dst, getcallerpc(unsafe.Pointer(&typ)), funcPC(reflect_typedmemmove))
+		raceReadObjectPC(typ, src, getcallerpc(unsafe.Pointer(&typ)), funcPC(reflect_typedmemmove))
+	}
+	if msanenabled {
+		msanwrite(dst, typ.size)
+		msanread(src, typ.size)
+	}
 	typedmemmove(typ, dst, src)
 }
 
@@ -300,7 +308,23 @@ func reflect_typedslicecopy(elemType *_type, dst, src slice) int {
 		if n > src.len {
 			n = src.len
 		}
-		memmove(dst.array, src.array, uintptr(n)*elemType.size)
+		if n == 0 {
+			return 0
+		}
+
+		size := uintptr(n) * elemType.size
+		if raceenabled {
+			callerpc := getcallerpc(unsafe.Pointer(&elemType))
+			pc := funcPC(reflect_typedslicecopy)
+			racewriterangepc(dst.array, size, callerpc, pc)
+			racereadrangepc(src.array, size, callerpc, pc)
+		}
+		if msanenabled {
+			msanwrite(dst.array, size)
+			msanread(src.array, size)
+		}
+
+		memmove(dst.array, src.array, size)
 		return n
 	}
 	return typedslicecopy(elemType, dst, src)
diff --git a/src/runtime/race/testdata/reflect_test.go b/src/runtime/race/testdata/reflect_test.go
new file mode 100644
index 0000000000..b567400156
--- /dev/null
+++ b/src/runtime/race/testdata/reflect_test.go
@@ -0,0 +1,46 @@
+// Copyright 2016 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.
+
+package race_test
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestRaceReflectRW(t *testing.T) {
+	ch := make(chan bool, 1)
+	i := 0
+	v := reflect.ValueOf(&i)
+	go func() {
+		v.Elem().Set(reflect.ValueOf(1))
+		ch <- true
+	}()
+	_ = v.Elem().Int()
+	<-ch
+}
+
+func TestRaceReflectWW(t *testing.T) {
+	ch := make(chan bool, 1)
+	i := 0
+	v := reflect.ValueOf(&i)
+	go func() {
+		v.Elem().Set(reflect.ValueOf(1))
+		ch <- true
+	}()
+	v.Elem().Set(reflect.ValueOf(2))
+	<-ch
+}
+
+func TestRaceReflectCopyWW(t *testing.T) {
+	ch := make(chan bool, 1)
+	a := make([]byte, 2)
+	v := reflect.ValueOf(a)
+	go func() {
+		reflect.Copy(v, v)
+		ch <- true
+	}()
+	reflect.Copy(v, v)
+	<-ch
+}