diff --git a/new/ui_darwin.h b/new/ui_darwin.h
index 159939c..64b01db 100644
--- a/new/ui_darwin.h
+++ b/new/ui_darwin.h
@@ -6,7 +6,7 @@
 #define MAC_OS_X_VERSION_MIN_REQUIRED MAC_OS_X_VERSION_10_7
 #define MAC_OS_X_VERSION_MAX_ALLOWED MAC_OS_X_VERSION_10_7
 #import <Cocoa/Cocoa.h>
-#import "ui.h"
+#import "uipriv.h"
 
 #define toNSString(str) [NSString stringWithUTF8String:(str)]
 
diff --git a/new/ui_unix.h b/new/ui_unix.h
index 82bcf7c..642dd49 100644
--- a/new/ui_unix.h
+++ b/new/ui_unix.h
@@ -8,6 +8,6 @@
 #define GDK_VERSION_MIN_REQUIRED GDK_VERSION_3_4
 #define GDK_VERSION_MAX_ALLOWED GDK_VERSION_3_4
 #include <gtk/gtk.h>
-#include "ui.h"
+#include "uipriv.h"
 
 #endif
diff --git a/new/ui_windows.h b/new/ui_windows.h
index 3545244..f0bbe2c 100644
--- a/new/ui_windows.h
+++ b/new/ui_windows.h
@@ -29,7 +29,7 @@
 #include <stdarg.h>
 #include <oleacc.h>
 #include <stdio.h>
-#include "ui.h"
+#include "uipriv.h"
 
 // alloc_windows.c
 extern void *uiAlloc(size_t);
diff --git a/new/uipriv.h b/new/uipriv.h
new file mode 100644
index 0000000..158d30c
--- /dev/null
+++ b/new/uipriv.h
@@ -0,0 +1,19 @@
+// 6 april 2015
+#include "ui.h"
+
+typedef struct uiSize uiSize;
+typedef struct uiSizing uiSizing;
+
+struct uiSize {
+	intmax_t width;
+	intmax_t height;
+};
+
+struct uiControl {
+	uintptr_t (*handle)(uiControl *);
+	void (*setParent)(uiControl *, uintptr_t);
+	uiSize (*preferredSize)(uiControl *, uiSizing *);
+	void (*resizing)(uiControl *, intmax_t, intmax_t, intmax_t, intmax_t, uiSizing *);
+	void (*containerShow)(uiControl *);
+	void (*containerHide)(uiControl *);
+};