diff --git a/cairo.c b/cairo.c
index 01b4441..bd4d3d3 100644
--- a/cairo.c
+++ b/cairo.c
@@ -2,24 +2,26 @@
 
 #include "pes.h"
 
-#define X(stitch) ((double)((stitch)->x - pes->min_x) * outw / width)
-#define Y(stitch) ((double)((stitch)->y - pes->min_y) * outh / height)
+#define X(stitch) (((stitch)->x - pes->min_x) * scale)
+#define Y(stitch) (((stitch)->y - pes->min_y) * scale)
 
 void output_cairo(struct pes *pes, const char *filename, int size)
 {
-	int width  = pes->max_x - pes->min_x + 1;
-	int height = pes->max_y - pes->min_y + 1;
-	int outw = width, outh = height;
+	int width  = pes->max_x - pes->min_x, outw;
+	int height = pes->max_y - pes->min_y, outh;
+	double scale = 1.0;
 	struct pes_block *block;
 	cairo_surface_t *surface;
 	cairo_t *cr;
 
 	if (size > 0) {
-		outw = size;
-		outh = size;
+		int maxd = width > height ? width : height;
+		scale = (double) size / maxd;
 	}
+	outw = width * scale;
+	outh = height * scale;
 
-	surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, outw, outh);
+	surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, outw+1, outh+1);
 	cr = cairo_create (surface);
 
 	block = pes->blocks;
@@ -35,7 +37,7 @@
 			++stitch;
 			cairo_line_to(cr, X(stitch), Y(stitch));
 		}
-		cairo_set_line_width (cr, 0.2);
+		cairo_set_line_width(cr, scale);
 		cairo_stroke(cr);
 
 		block = block->next;