diff --git a/gerber/render/cairo_backend.py b/gerber/render/cairo_backend.py
index 2791d76..0ae5d40 100644
--- a/gerber/render/cairo_backend.py
+++ b/gerber/render/cairo_backend.py
@@ -154,7 +154,9 @@ class GerberCairoContext(GerberContext):
             self.surface_buffer.flush()
 
             with open(filename, "w") as f:
-                f.write(open(self.surface_buffer.name, "r").read())
+                self.surface_buffer.seek(0)
+                f.write(self.surface_buffer.read())
                 f.flush()
+
         else:
             self.surface.write_to_png(filename)