diff --git a/dios/dios.py b/dios/dios.py
index 06fe332248bd339cd4ed3c6d3937ea264974a6f5..28eba26c770207a26be2fc17392b1d628d306daa 100644
--- a/dios/dios.py
+++ b/dios/dios.py
@@ -434,11 +434,6 @@ class DictOfSeries:
     def __deepcopy__(self, memo=None):
         return self.copy(deep=True)
 
-    def copy_empty(self):
-        new = DictOfSeries()
-        new._itype = self.itype
-        return new
-
     def copy(self, deep=True):
         new = self.copy_empty()
         # We use `_data` here, because all checks are already done.
@@ -449,6 +444,11 @@ class DictOfSeries:
             new._data[k] = self._data[k].copy(deep=deep)
         return new
 
+    def copy_empty(self):
+        new = DictOfSeries()
+        new._itype = self.itype
+        return new
+
     def __op1__(self, op):
         new = self.copy_empty()
         for k in self.columns: