diff --git a/IPython/nbconvert/transformers/svg2pdf.py b/IPython/nbconvert/transformers/svg2pdf.py
index b6d7347..0a2e0da 100644
--- a/IPython/nbconvert/transformers/svg2pdf.py
+++ b/IPython/nbconvert/transformers/svg2pdf.py
@@ -91,4 +91,4 @@ class SVG2PDFTransformer(ConvertFiguresTransformer):
                     # PDF is a nb supported binary, data type, so base64 encode.
                     return base64.encodestring(f.read())
             else:
-                return TypeError("Inkscape svg to png conversion failed")
+                raise TypeError("Inkscape svg to png conversion failed")