diff --git a/brush.c b/brush.c
index b88e38c9..09e4150e 100644
--- a/brush.c
+++ b/brush.c
@@ -1293,7 +1293,7 @@ void Stretch_brush_preview(short x1, short y1, short x2, short y2)
 }
 
 /// Returns the minimum of 4 integers.
-int Min4(int a,int b,int c,int d)
+int Min4(unsigned long int a,unsigned long int b,unsigned long int c,unsigned long int d)
 {
   if (a<b)
     if (c<d)
@@ -1321,7 +1321,7 @@ void Pixel_in_distort_buffer(word x_pos,word y_pos,byte color)
 }
 
 /// Returns the maximum of 4 integers.
-int Max4(int a,int b,int c,int d)
+int Max4(unsigned long int a,unsigned long int b,unsigned long int c,unsigned long int d)
 {
   if (a>b)
     if (c>d)
@@ -1336,22 +1336,22 @@ int Max4(int a,int b,int c,int d)
 }
 
 // Recursive function for linear distortion.
-void Draw_brush_linear_distort(long int tex_min_x,
-                               long int tex_min_y,
-                               long int tex_max_x,
-                               long int tex_max_y,
-                               long int x1,
-                               long int y1,
-                               long int x2,
-                               long int y2,
-                               long int x3,
-                               long int y3,
-                               long int x4,
-                               long int y4)
+void Draw_brush_linear_distort(unsigned long int tex_min_x,
+                               unsigned long int tex_min_y,
+                               unsigned long int tex_max_x,
+                               unsigned long int tex_max_y,
+                               unsigned long int x1,
+                               unsigned long int y1,
+                               unsigned long int x2,
+                               unsigned long int y2,
+                               unsigned long int x3,
+                               unsigned long int y3,
+                               unsigned long int x4,
+                               unsigned long int y4)
 {
   static byte color;
   // bounding rectangle
-  static long int min_x, max_x, min_y, max_y;
+  static unsigned long int min_x, max_x, min_y, max_y;
   
   min_x=Min4(x1,x2,x3,x4);
   max_x=Max4(x1,x2,x3,x4);
@@ -1430,7 +1430,7 @@ void Draw_brush_linear_distort(long int tex_min_x,
 }
 
 /// Draws a distorted version of the brush, mapped over the given quad (picture coordinates).
-void Distort_brush_preview(short x1, short y1, short x2, short y2, short x3, short y3, short x4, short y4)
+void Distort_brush_preview(unsigned short x1, unsigned short y1, unsigned short x2, unsigned short y2, unsigned short x3, unsigned short y3, unsigned short x4, unsigned short y4)
 {
   Pixel_for_distort=Pixel_figure_preview;
   Draw_brush_linear_distort(0, 0, (Brush_width<<16), (Brush_height<<16), (x1<<16), (y1<<16), (x2<<16), (y2<<16), (x3<<16), (y3<<16), (x4<<16), (y4<<16));
diff --git a/brush.h b/brush.h
index e2e09a02..030cdb74 100644
--- a/brush.h
+++ b/brush.h
@@ -72,7 +72,7 @@ void Rotate_brush_preview(float angle);
 /*!
     Distort the brush on the screen.
 */
-void Distort_brush_preview(short x1, short y1, short x2, short y2, short x3, short y3, short x4, short y4);
+void Distort_brush_preview(unsigned short x1, unsigned short y1, unsigned short x2, unsigned short y2, unsigned short x3, unsigned short y3, unsigned short x4, unsigned short y4);
 
 /*!
     Replace the brush by a distorted version of itself.