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)