diff --git a/pygtfs/gtfs_entities.py b/pygtfs/gtfs_entities.py
index a84f015..8244006 100644
--- a/pygtfs/gtfs_entities.py
+++ b/pygtfs/gtfs_entities.py
@@ -82,13 +82,9 @@ def in_range(self, key, value):
 def _validate_float_none(*field_names):
     @validates(*field_names)
     def is_float_none(self, key, value):
-        try:
-            return float(value)
-        except ValueError:
-            if value is None or value == "":
-                return None
-            else:
-                raise
+        if value is None or value == "":
+            return None
+        return float(value)
     return is_float_none