diff --git a/src/os/pipe_test.go b/src/os/pipe_test.go
index b3d5380b8da..b6636185029 100644
--- a/src/os/pipe_test.go
+++ b/src/os/pipe_test.go
@@ -462,7 +462,7 @@ func TestFdReadRace(t *testing.T) {
 		// Give the other goroutine a chance to enter the Read.
 		// It doesn't matter if this occasionally fails, the test
 		// will still pass, it just won't test anything.
-		//time.Sleep(10 * time.Millisecond)
+		time.Sleep(10 * time.Millisecond)
 		r.Fd()
 
 		// The bug was that Fd would hang until Read timed out.