diff --git a/visualizer.py b/visualizer.py
index ce42fb54eed3a412e519cc0e85e1a5951cea2a4b..4fbf36b7597255098b370b16382c761660b4c03e 100755
--- a/visualizer.py
+++ b/visualizer.py
@@ -51,7 +51,7 @@ def filtered_float(s):
 
 ONE_HOUR_DATA = asccol.DataSpec(
     leading=2,  # 2 lines to delete
-    cols=asccol.Columns(
+    cols=(
         ('year', int, 4),  # name, type (converter function), width
         ('jdate', int, 4),
         ('month', int, 3),
@@ -66,7 +66,7 @@ ONE_HOUR_DATA = asccol.DataSpec(
     ),
 )
 SOUTH_POLE_DATA = asccol.DataSpec(
-    cols=asccol.Columns(
+    cols=(
         ('year', int, 5),
         ('month', int, 5),
         ('day', int, 5),