diff --git a/desmume/src/windows/filter/2xsai.cpp b/desmume/src/windows/filter/2xsai.cpp
index af72bd569..5cd35a734 100644
--- a/desmume/src/windows/filter/2xsai.cpp
+++ b/desmume/src/windows/filter/2xsai.cpp
@@ -3,11 +3,6 @@
 
 //ref: http://vba-rerecording.googlecode.com/svn/trunk/src/2xsai.cpp
 
-typedef unsigned char u8;
-typedef unsigned short u16;
-typedef unsigned int u32;
-typedef int s32;
-
 static u32 colorMask = 0xfefefe;
 static u32 lowPixelMask = 0x010101;
 static u32 qcolorMask = 0xfcfcfc;
@@ -1184,4 +1179,4 @@ void RenderSuperEagle (SSurface Src, SSurface Dst)
                 lpSrc,
                 lpDst, Dst.Pitch*2, Src.Width, Src.Height);
 
-}
\ No newline at end of file
+}
diff --git a/desmume/src/windows/filter/filter.h b/desmume/src/windows/filter/filter.h
index eea59e3eb..a3900f563 100644
--- a/desmume/src/windows/filter/filter.h
+++ b/desmume/src/windows/filter/filter.h
@@ -16,12 +16,12 @@ along with the this software.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 
-struct SSurface {
+typedef struct {
 	unsigned char *Surface;
 
 	unsigned int Pitch;
 	unsigned int Width, Height;
-};
+} SSurface;
 
 void RenderNearest2X (SSurface Src, SSurface Dst);
 void RenderLQ2X (SSurface Src, SSurface Dst);
diff --git a/desmume/src/windows/filter/interp.h b/desmume/src/windows/filter/interp.h
index d647928d9..dad92d4c6 100644
--- a/desmume/src/windows/filter/interp.h
+++ b/desmume/src/windows/filter/interp.h
@@ -31,9 +31,7 @@
 #ifndef __INTERP_H
 #define __INTERP_H
 
-typedef unsigned char u8;
-typedef unsigned short u16;
-typedef unsigned int u32;
+#include "types.h"
 
 /***************************************************************************/
 /* Basic types */
@@ -278,7 +276,7 @@ static int interp_32_diff(u32 p1, u32 p2)
 
 #define INTERP_LIMIT2 (96000)
 //#define ABS(x) ((x) < 0 ? -(x) : (x))
-static __forceinline unsigned int ABS(int x) { return (x+(x>>31))^(x>>31); } // faster
+static FORCEINLINE u32 ABS(s32 x) { return (x+(x>>31))^(x>>31); } // faster
 #define MAX(x,y) ((x) > (y) ? (x) : (y))
 #define MIN(x,y) ((x) < (y) ? (x) : (y))
 //