diff --git a/NDHTMLtoPDF.h b/NDHTMLtoPDF.h
index 647646c..6a20cfd 100644
--- a/NDHTMLtoPDF.h
+++ b/NDHTMLtoPDF.h
@@ -9,8 +9,8 @@
 
 #import <UIKit/UIKit.h>
 
-#define kPaperSizeA4 CGSizeMake(595.2,841.8)
-#define kPaperSizeLetter CGSizeMake(612,792)
+#define kNDPaperSizeA4 CGSizeMake(595.2,841.8)
+#define kNDPaperSizeLetter CGSizeMake(612,792)
 
 @class NDHTMLtoPDF;