diff --git a/components/virtualtreeview-unstable/units/gtk/mmsystem.pas b/components/virtualtreeview-unstable/units/gtk/mmsystem.pas
new file mode 100644
index 000000000..e43b224cd
--- /dev/null
+++ b/components/virtualtreeview-unstable/units/gtk/mmsystem.pas
@@ -0,0 +1,34 @@
+unit mmsystem;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, Types;
+  
+function timeBeginPeriod(x1: DWord): DWord;
+
+function timeEndPeriod(x1: DWord): DWord;
+
+function timeGetTime: DWORD;
+
+implementation
+
+function timeBeginPeriod(x1: DWord): DWord;
+begin
+
+end;
+
+function timeEndPeriod(x1: DWord): DWord;
+begin
+
+end;
+
+function timeGetTime: DWORD;
+begin
+
+end;
+
+end.
+