commctrl.h must include prsht.h.

diff --git a/include/commctrl.h b/include/commctrl.h
index adc0fdb..0386f13 100644
--- a/include/commctrl.h
+++ b/include/commctrl.h
@@ -8,6 +8,7 @@
 #include "windef.h"
 #include "winuser.h"
 #include "imagelist.h"
+#include "prsht.h"
 
 /* c++ likes nameless unions whereas c doesnt */
 /* (used in property sheet structures)        */