diff --git a/arm9/source/common/hid.c b/arm9/source/common/hid.c
index 0eecaa4..9eaed2a 100644
--- a/arm9/source/common/hid.c
+++ b/arm9/source/common/hid.c
@@ -30,21 +30,25 @@ u32 HID_ReadRawTouchState(void)
 static fixp_t ts_mult[2];
 
 // ts_org indicates the coordinate system origin
-static u32 ts_org[2];
+static int ts_org[2];
 void HID_ReadTouchState(u16 *x, u16 *y)
 {
     u32 ts;
+    int xc, yc;
     fixp_t tx, ty;
 
     ts = HID_ReadRawTouchState();
     tx = INT_TO_FIXP(HID_RAW_TX(ts) - HID_TOUCH_MIDPOINT);
     ty = INT_TO_FIXP(HID_RAW_TY(ts) - HID_TOUCH_MIDPOINT);
 
-    *x = FIXP_TO_INT(fixp_round(fixp_product(tx, ts_mult[0]))) + ts_org[0];
-    *y = FIXP_TO_INT(fixp_round(fixp_product(ty, ts_mult[1]))) + ts_org[1];
+    xc = FIXP_TO_INT(fixp_round(fixp_product(tx, ts_mult[0]))) + ts_org[0];
+    yc = FIXP_TO_INT(fixp_round(fixp_product(ty, ts_mult[1]))) + ts_org[1];
+
+    *x = clamp(xc, 0, (ts_org[0] * 2) - 1);
+    *y = clamp(yc, 0, (ts_org[1] * 2) - 1);
 }
 
-bool HID_SetCalibrationData(const HID_CalibrationData *calibs, int point_cnt, u32 screen_w, u32 screen_h)
+bool HID_SetCalibrationData(const HID_CalibrationData *calibs, int point_cnt, int screen_w, int screen_h)
 {
     int mid_x, mid_y;
     fixp_t avg_x, avg_y;
diff --git a/arm9/source/common/hid.h b/arm9/source/common/hid.h
index 4b7b825..f3c8e62 100644
--- a/arm9/source/common/hid.h
+++ b/arm9/source/common/hid.h
@@ -24,7 +24,7 @@ typedef struct {
 
 u32 HID_ReadRawTouchState(void);
 void HID_ReadTouchState(u16 *x, u16 *y);
-bool HID_SetCalibrationData(const HID_CalibrationData *calibs, int point_cnt, u32 screen_w, u32 screen_h);
+bool HID_SetCalibrationData(const HID_CalibrationData *calibs, int point_cnt, int screen_w, int screen_h);
 
 u32 InputWait(u32 timeout_sec);
 bool CheckButton(u32 button);
diff --git a/arm9/source/common/ui.c b/arm9/source/common/ui.c
index 3e3284f..1c44052 100644
--- a/arm9/source/common/ui.c
+++ b/arm9/source/common/ui.c
@@ -1072,7 +1072,7 @@ static void DrawSimpleCircle(unsigned char *screen, int x, int y, int color, int
 
 bool ShowCalibrationDialog(void)
 {
-    int current_dot;
+    u32 current_dot;
     static const u32 dot_positions[][2] = {
         {16, 16},
         {320 - 16, 240 - 16},
@@ -1089,7 +1089,7 @@ bool ShowCalibrationDialog(void)
 
     current_dot = 0;
     while(current_dot < countof(dot_positions)) {
-        for (int i = 0; i < current_dot; i++)
+        for (u32 i = 0; i < current_dot; i++)
             DrawSimpleCircle(BOT_SCREEN, dot_positions[i][0], dot_positions[i][1], COLOR_BRIGHTGREEN, COLOR_BLACK);
         DrawSimpleCircle(BOT_SCREEN, dot_positions[current_dot][0], dot_positions[current_dot][1], COLOR_RED, COLOR_BLACK);
         for (u32 i = current_dot+1; i < countof(dot_positions); i++)
diff --git a/common/common.h b/common/common.h
index 211e45d..39c400f 100755
--- a/common/common.h
+++ b/common/common.h
@@ -31,6 +31,9 @@
 #define int_sign(x) \
     (((x) > 0) - ((x) < 0))
 
+#define clamp(x, min, max) \
+    ((x) < (max) ? ((x) > (min) ? (x) : (min)) : (max))
+
 #define getbe16(d) \
     (((d)[0]<<8) | (d)[1])
 #define getbe32(d) \