diff --git a/firanka/series/range.py b/firanka/series/range.py
index 6648df0d17e78cd0ba81dc067284c7788f06543c..1079d5d16f7d9d287a7bad25974ba0a9d5baa81f 100644
--- a/firanka/series/range.py
+++ b/firanka/series/range.py
@@ -38,7 +38,7 @@ class Range(object):
     def __init__(self, *args):
         if len(args) == 1:
             rs, = args
-            args = self.__from_range(rs) if isinstance(rs, type(self)) else self.__from_str(rs)
+            args = (self.__from_range if isinstance(rs, type(self)) else self.__from_str)(rs)
 
         if args[2] and math.isinf(args[0]):
             raise ValueError('Greater or equal with infinity!')