diff --git a/solidify/overlap.c b/solidify/overlap.c
index 4ecec71..96ff593 100644
--- a/solidify/overlap.c
+++ b/solidify/overlap.c
@@ -185,10 +185,10 @@ static void merge_matrix(struct matrix *m, const struct solid *s,
 
 	m->a[0][0] *= f_x;
 	m->a[0][1] *= f_x;
-	m->b[0] *= f_x;
+//	m->b[0] *= f_x;
 	m->a[1][0] *= f_y;
 	m->a[1][1] *= f_y;
-	m->b[1] *= f_y;
+//	m->b[1] *= f_y;
 
 	/*
 	 * The transformation matrix f->m describes a transformation of
diff --git a/solidify/project.c b/solidify/project.c
index 792d3fc..10e703d 100644
--- a/solidify/project.c
+++ b/solidify/project.c
@@ -67,7 +67,7 @@ static void read_face_data(FILE *file, struct face *f)
 
 	if (fscanf(file, "%f", &v) != 1)
 		return;
-	f->z_ref = v/f->z_step;
+	f->z_ref = round(v/f->z_step);
 
 	if (fscanf(file, "%f", &v) != 1)
 		return;