diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index 7be9f67826497..3150cdf30e560 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -1118,7 +1118,7 @@ def _helper_csvexcel(self, writer, na_rep=None, cols=None,
 
     def to_csv(self, path_or_buf, sep=",", na_rep='', float_format=None,
                cols=None, header=True, index=True, index_label=None,
-               mode='w', nanRep=None, encoding=None, quoting=None):
+               mode='w', nanRep=None, encoding='utf-8', quoting=None):
         """
         Write DataFrame to a comma-separated values (csv) file
 
@@ -1168,13 +1168,10 @@ def to_csv(self, path_or_buf, sep=",", na_rep='', float_format=None,
             quoting = csv.QUOTE_MINIMAL
 
         try:
-            if encoding is not None:
-                csvout = com.UnicodeWriter(f, lineterminator='\n',
-                                           delimiter=sep, encoding=encoding,
-                                           quoting=quoting)
-            else:
-                csvout = csv.writer(f, lineterminator='\n', delimiter=sep,
-                                    quoting=quoting)
+            csvout = com.UnicodeWriter(f, lineterminator='\n',
+                                        delimiter=sep, encoding=encoding,
+                                        quoting=quoting)
+
             self._helper_csvexcel(csvout, na_rep=na_rep,
                                   float_format=float_format, cols=cols,
                                   header=header, index=index,
diff --git a/pandas/core/series.py b/pandas/core/series.py
index 7400aa5bde2e7..6eac2679d5dc7 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -1151,7 +1151,7 @@ def max(self, axis=None, out=None, skipna=True, level=None):
 
     @Substitution(name='standard deviation', shortname='stdev',
                   na_action=_doc_exclude_na, extras='')
-    @Appender(_stat_doc + 
+    @Appender(_stat_doc +
         """
         Normalized by N-1 (unbiased estimator).
         """)
@@ -1164,7 +1164,7 @@ def std(self, axis=None, dtype=None, out=None, ddof=1, skipna=True,
 
     @Substitution(name='variance', shortname='var',
                   na_action=_doc_exclude_na, extras='')
-    @Appender(_stat_doc + 
+    @Appender(_stat_doc +
         """
         Normalized by N-1 (unbiased estimator).
         """)
@@ -2419,7 +2419,7 @@ def from_csv(cls, path, sep=',', parse_dates=True, header=None,
 
     def to_csv(self, path, index=True, sep=",", na_rep='',
                float_format=None, header=False,
-               index_label=None, mode='w', nanRep=None, encoding=None):
+               index_label=None, mode='w', nanRep=None, encoding='utf-8'):
         """
         Write Series to a comma-separated values (csv) file