diff --git a/src/pkg/os/exec_windows.go b/src/pkg/os/exec_windows.go
index bac33b908b..991099d4f4 100644
--- a/src/pkg/os/exec_windows.go
+++ b/src/pkg/os/exec_windows.go
@@ -17,7 +17,7 @@ func (p *Process) Wait(options int) (w *Waitmsg, err Error) {
 	case syscall.WAIT_FAILED:
 		return nil, NewSyscallError("WaitForSingleObject", e)
 	default:
-		return nil, ErrorString("os: unexpected result from WaitForSingleObject")
+		return nil, NewError("os: unexpected result from WaitForSingleObject")
 	}
 	var ec uint32
 	e = syscall.GetExitCodeProcess(int32(p.handle), &ec)