diff --git a/cairo.c b/cairo.c
index 23dd628..0683848 100644
--- a/cairo.c
+++ b/cairo.c
@@ -28,6 +28,9 @@
 		struct stitch *stitch = block->stitch;
 		int i;
 
+		if (!block->nr_stitches)
+			continue;
+
 		cairo_set_source_rgb(cr, c->r / 255.0, c->g / 255.0, c->b / 255.0);
 		cairo_move_to(cr, X(stitch), Y(stitch));
 
diff --git a/svg.c b/svg.c
index 1237a64..d1c81f0 100644
--- a/svg.c
+++ b/svg.c
@@ -14,6 +14,9 @@
 		pes->max_y - pes->min_y);
 
 	for (struct pes_block *block = pes->blocks; block; block = block->next) {
+		if (!block->nr_stitches)
+			continue;
+
 		int i;
 		printf("<path stroke=\"#%02x%02x%02x\" fill=\"none\" d=\"M %d %d",
 			block->color->r,