diff --git a/src/calibre/ebooks/pdf/render/graphics.py b/src/calibre/ebooks/pdf/render/graphics.py
index 760feece86..b08b4d9cc9 100644
--- a/src/calibre/ebooks/pdf/render/graphics.py
+++ b/src/calibre/ebooks/pdf/render/graphics.py
@@ -410,7 +410,7 @@ class Graphics(object):
             try:
                 w /= sqrt(t.m11()**2 + t.m22()**2)
             except ZeroDivisionError:
-                w = 0
+                pass
         pdf.serialize(w)
         pdf.current_page.write(' w ')