diff --git a/robotgo.go b/robotgo.go
index ab7203f..8408840 100644
--- a/robotgo.go
+++ b/robotgo.go
@@ -984,3 +984,8 @@ func FindIds(name string) ([]int32, error) {
 
 	return pids, err
 }
+
+// ActivePID window active by PID
+func ActivePID(pid int32) {
+	C.active_PID(C.int32(pid))
+}
diff --git a/window/goWindow.h b/window/goWindow.h
index 973f537..6d4a90e 100644
--- a/window/goWindow.h
+++ b/window/goWindow.h
@@ -57,6 +57,19 @@ void aSetActive(const MData win){
 	SetActive(win);
 }
 
+void active_PID(int32 pid){
+	MData win;
+	#if defined(IS_MACOSX)
+		// Handle to a AXUIElementRef
+		win.AxID = AXUIElementCreateApplication(pid);
+	#elif defined(USE_X11)
+		win.XWin = Window(pid);		// Handle to an X11 window
+	#elif defined(IS_WINDOWS)
+		win.HWnd = HWND(pid);		// Handle to a window HWND
+	#endif
+	SetActive(win);
+}
+
 MData aGetActive(){
 	MData mdata = GetActive();
 	return mdata;