diff --git a/demos/modules/gwin/graph/main.c b/demos/modules/gwin/graph/main.c
index 7a496fae..4273b750 100644
--- a/demos/modules/gwin/graph/main.c
+++ b/demos/modules/gwin/graph/main.c
@@ -82,14 +82,14 @@ int main(void) {
 	gwinGraphDrawAxis(gh);
 	
 	for(i = 0; i < gwinGetWidth(gh); i++)
-		gwinGraphDrawPoint(gh, i-gwinGetWidth(gh)/2, 80*fsin(2*i/5));	//sin(2*0.2*M_PI*i/180));
+		gwinGraphDrawPoint(gh, i-gwinGetWidth(gh)/2, 80*fsin(2*i/5));	//sin(2*0.2*GFX_PI*i/180));
 
 	gwinGraphStartSet(gh);
 	GraphStyle1.point.color = Green;
 	gwinGraphSetStyle(gh, &GraphStyle1);
 	
 	for(i = 0; i < gwinGetWidth(gh)*5; i++)
-		gwinGraphDrawPoint(gh, i/5-gwinGetWidth(gh)/2, 95*fsin(2*i/5));	//sin(2*0.2*M_PI*i/180));
+		gwinGraphDrawPoint(gh, i/5-gwinGetWidth(gh)/2, 95*fsin(2*i/5));	//sin(2*0.2*GFX_PI*i/180));
 
 	gwinGraphStartSet(gh);
 	gwinGraphSetStyle(gh, &GraphStyle2);
diff --git a/src/gdisp/gdisp.c b/src/gdisp/gdisp.c
index 25fa2c4e..3c0bab9c 100644
--- a/src/gdisp/gdisp.c
+++ b/src/gdisp/gdisp.c
@@ -1725,8 +1725,8 @@ void gdispGBlitArea(GDisplay *g, coord_t x, coord_t y, coord_t cx, coord_t cy, c
 			sedge = round(radius * ((sbit & 0x99) ? fsin(start) : fcos(start)));
 			eedge = round(radius * ((ebit & 0x99) ? fsin(end) : fcos(end)));
 		#else
-			sedge = round(radius * ((sbit & 0x99) ? sin(start*M_PI/180) : cos(start*M_PI/180)));
-			eedge = round(radius * ((ebit & 0x99) ? sin(end*M_PI/180) : cos(end*M_PI/180)));
+			sedge = round(radius * ((sbit & 0x99) ? sin(start*GFX_PI/180) : cos(start*GFX_PI/180)));
+			eedge = round(radius * ((ebit & 0x99) ? sin(end*GFX_PI/180) : cos(end*GFX_PI/180)));
 		#endif
 		if (sbit & 0xB4) sedge = -sedge;
 		if (ebit & 0xB4) eedge = -eedge;
@@ -1852,8 +1852,8 @@ void gdispGBlitArea(GDisplay *g, coord_t x, coord_t y, coord_t cx, coord_t cy, c
 			sxb = FP2FIXED(radius*fcos(start));	sy = -round(radius*fsin(start));
 			exb = FP2FIXED(radius*fcos(end));	ey = -round(radius*fsin(end));
 		#else
-			sxb = FP2FIXED(radius*cos(start*M_PI/180));	sy = -round(radius*sin(start*M_PI/180));
-			exb = FP2FIXED(radius*cos(end*M_PI/180));	ey = -round(radius*sin(end*M_PI/180));
+			sxb = FP2FIXED(radius*cos(start*GFX_PI/180));	sy = -round(radius*sin(start*GFX_PI/180));
+			exb = FP2FIXED(radius*cos(end*GFX_PI/180));	ey = -round(radius*sin(end*GFX_PI/180));
 		#endif
 		sxd = sy ? sxb/sy : sxb;
 		exd = ey ? exb/ey : exb;
diff --git a/src/gmisc/gmisc.h b/src/gmisc/gmisc.h
index 7ce91442..aa845261 100644
--- a/src/gmisc/gmisc.h
+++ b/src/gmisc/gmisc.h
@@ -75,14 +75,14 @@ typedef int32_t	fixed;
 /**
  * @brief   The famous number pi
  */
-#ifndef PI
-	#define PI	3.1415926535897932384626433832795028841971693993751
+#ifndef GFX_PI
+	#define GFX_PI	3.1415926535897932384626433832795028841971693993751
 #endif
 
 /**
  * @brief   pi as a fixed point
  */
-#define FIXED_PI	FP2FIXED(PI)
+#define FIXED_PI	FP2FIXED(GFX_PI)
 
 /*===========================================================================*/
 /* External declarations.                                                    */
diff --git a/src/gmisc/gmisc_matrix2d.c b/src/gmisc/gmisc_matrix2d.c
index 2cd162f2..352afbe7 100644
--- a/src/gmisc/gmisc_matrix2d.c
+++ b/src/gmisc/gmisc_matrix2d.c
@@ -75,7 +75,7 @@ void gmiscMatrixFloat2DApplyRotation(MatrixFloat2D *dst, const MatrixFloat2D *sr
 		s = fsin(angle);
 		c = fcos(angle);
 	#else
-		c = angle*M_PI/180;
+		c = angle*GFX_PI/180;
 		s = sin(c);
 		c = cos(c);
 	#endif