Index: headers/OGBox.h
==================================================================
--- headers/OGBox.h
+++ headers/OGBox.h
@@ -21,11 +21,11 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
 #import "OGWidget.h"
 
-#ifdef OG_W32
+#ifdef OG_WIN32
 typedef struct s_OGBoxChild
 {
 	HWND  hwnd;
 	BOOL  expand;
 	BOOL  fill;
@@ -35,11 +35,11 @@
 	struct s_OGBoxChild *next;
 } OGBoxChild;
 #endif
 
 @interface OGBox: OGWidget
-#ifdef OG_W32
+#ifdef OG_WIN32
 { OGBoxChild *firstBorn; }
 - (void)resizeChildren;
 #endif
 + box;
 - (void)appendChild: (OGWidget*)child

Index: headers/OGComboBox.h
==================================================================
--- headers/OGComboBox.h
+++ headers/OGComboBox.h
@@ -41,11 +41,11 @@
 {
 	id <OGComboBoxDelegate> delegate;
 	id <OGComboBoxDataSource> dataSource;
 }
 
-#ifdef OG_W32
+#ifdef OG_WIN32
 //unfortunately, the built-in Win32 ListBox stores a pointer to it's parent (for sending selection changed notifications) during CreateWindow().
 //it does not update it after a SetParent()... unless we implement a custom ListBox control i don't see a way around this...
 - initWithParent : (OGWidget *)parent;
 #endif
 

Index: headers/OGWidget.h
==================================================================
--- headers/OGWidget.h
+++ headers/OGWidget.h
@@ -19,35 +19,32 @@
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifdef OG_GTK
+#if defined(OG_GTK)
 # include <gtk/gtk.h>
-#endif
-#ifdef OG_W32
+#elif defined(OG_WIN32)
 # include <windows.h>
 #endif
 
 #import <ObjFW/ObjFW.h>
 
 @interface OGWidget: OFObject
 {
 @public
-#ifdef OG_GTK
+#if defined(OG_GTK)
 	GtkWidget *widget;
-#endif
-#ifdef OG_W32
+#elif defined(OG_WIN32)
 	HWND widget;
 #endif
 }
 
 - (void)show;
 - (void)hide;
 @end
 
-#ifdef OG_GTK
+#if defined(OG_GTK)
 extern void og_destroy(GtkWidget*, OGWidget*);
-#endif
-#ifdef OG_W32
+#elif defined(OG_WIN32)
 extern void og_destroy(HWND widget, OGWidget *object);
 #endif

Index: win32/Makefile
==================================================================
--- win32/Makefile
+++ win32/Makefile
@@ -1,12 +1,12 @@
 PREFIX ?= /usr/local
 
 all : test.exe
 
 %.o : %.m
-	gcc -g -DOG_W32 -I../headers -c -o $@ $^ `objfw-config --cppflags --objcflags`
+	gcc -g -DOG_WIN32 -I../headers -c -o $@ $^ `objfw-config --cppflags --objcflags`
 
 test.exe : OGApplication.o OGWidget.o OGWindow.o OGBox.o OGVBox.o OGHBox.o OGButton.o OGComboBox.o OGComboBoxItem.o test.o
 	gcc -mwindows -o test.exe *.o `objfw-config --libs`
 
 clean :
 	rm -f *.exe *.o