diff --git a/pandas/core/series.py b/pandas/core/series.py
index d339a93a3ed9b..7962da7e2441f 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -1196,7 +1196,7 @@ def drop_duplicates(self, keep='first', inplace=False):
     def duplicated(self, keep='first'):
         return super(Series, self).duplicated(keep=keep)
 
-    def idxmin(self, axis=None, out=None, skipna=True):
+    def idxmin(self, axis=None, skipna=True):
         """
         Index of first occurrence of minimum of values.
 
@@ -1223,7 +1223,7 @@ def idxmin(self, axis=None, out=None, skipna=True):
             return np.nan
         return self.index[i]
 
-    def idxmax(self, axis=None, out=None, skipna=True):
+    def idxmax(self, axis=None, skipna=True):
         """
         Index of first occurrence of maximum of values.