diff --git a/pygments/util.py b/pygments/util.py

index 46c5a12..4710924 100644

--- a/pygments/util.py

+++ b/pygments/util.py

@@ -118,7 +118,7 @@ def make_analysator(f):

             return 0.0

         try:

             return min(1.0, max(0.0, float(rv)))

-        except ValueError:

+        except (ValueError, TypeError):

             return 0.0

     text_analyse.__doc__ = f.__doc__

     return staticmethod(text_analyse)