diff --git a/src/cmd/go/script_test.go b/src/cmd/go/script_test.go
index 3ad0608725..5e82929f19 100644
--- a/src/cmd/go/script_test.go
+++ b/src/cmd/go/script_test.go
@@ -521,6 +521,7 @@ var scriptCmds = map[string]func(*testScript, simpleStatus, []string){
 	"mv":      (*testScript).cmdMv,
 	"rm":      (*testScript).cmdRm,
 	"skip":    (*testScript).cmdSkip,
+	"sleep":   (*testScript).cmdSleep,
 	"stale":   (*testScript).cmdStale,
 	"stderr":  (*testScript).cmdStderr,
 	"stdout":  (*testScript).cmdStdout,
@@ -921,6 +922,21 @@ func (ts *testScript) cmdSkip(want simpleStatus, args []string) {
 	ts.t.Skip()
 }
 
+// sleep sleeps for the given duration
+func (ts *testScript) cmdSleep(want simpleStatus, args []string) {
+	if len(args) != 1 {
+		ts.fatalf("usage: sleep duration")
+	}
+	d, err := time.ParseDuration(args[0])
+	if err != nil {
+		ts.fatalf("sleep: %v", err)
+	}
+	if want != success {
+		ts.fatalf("unsupported: %v sleep", want)
+	}
+	time.Sleep(d)
+}
+
 // stale checks that the named build targets are stale.
 func (ts *testScript) cmdStale(want simpleStatus, args []string) {
 	if len(args) == 0 {
diff --git a/src/cmd/go/testdata/script/README b/src/cmd/go/testdata/script/README
index 85e575d56e..c575bff1a5 100644
--- a/src/cmd/go/testdata/script/README
+++ b/src/cmd/go/testdata/script/README
@@ -176,6 +176,11 @@ The commands are:
 - skip [message]
   Mark the test skipped, including the message if given.
 
+- sleep duration
+  Sleep for the given duration (a time.Duration string).
+  (Tests should generally poll instead of sleeping, but sleeping may sometimes
+  be necessary, for example, to ensure that modified files have unique mtimes.)
+
 - [!] stale path...
   The packages named by the path arguments must (or must not)
   be reported as "stale" by the go command.