diff --git a/src/os/exec.go b/src/os/exec.go
index b3f60b62d03..a7f8710b955 100644
--- a/src/os/exec.go
+++ b/src/os/exec.go
@@ -88,6 +88,11 @@ func FindProcess(pid int) (*Process, error) {
 // specified by name, argv and attr. The argv slice will become os.Args in the
 // new process, so it normally starts with the program name.
 //
+// If the calling goroutine has locked the operating system thread
+// with runtime.LockOSThread and modified any inheritable OS-level
+// thread state (for example, Linux or Plan 9 name spaces), the new
+// process will inherit the caller's thread state.
+//
 // StartProcess is a low-level interface. The os/exec package provides
 // higher-level interfaces.
 //
diff --git a/src/os/exec/exec.go b/src/os/exec/exec.go
index 8a49fe3b58e..5ef9540141e 100644
--- a/src/os/exec/exec.go
+++ b/src/os/exec/exec.go
@@ -293,6 +293,11 @@ func (c *Cmd) closeDescriptors(closers []io.Closer) {
 //
 // If the command starts but does not complete successfully, the error is of
 // type *ExitError. Other error types may be returned for other situations.
+//
+// If the calling goroutine has locked the operating system thread
+// with runtime.LockOSThread and modified any inheritable OS-level
+// thread state (for example, Linux or Plan 9 name spaces), the new
+// process will inherit the caller's thread state.
 func (c *Cmd) Run() error {
 	if err := c.Start(); err != nil {
 		return err