diff --git a/doc/latex.rst b/doc/latex.rst
index 03221201db..c80ee33551 100644
--- a/doc/latex.rst
+++ b/doc/latex.rst
@@ -531,6 +531,10 @@ Keys that don't need to be overridden unless in special cases are:
       Changed default for ``'pdflatex'``. Previously it was using 
       ``'\\fvset{fontsize=\\small}'``.
 
+   .. versionchanged:: 4.1.0
+      Changed default for Chinese documents to
+      ``'\\fvset{fontsize=\\small,formatcom=\\xeCJKVerbAddon}'``
+
 Keys that are set by other options and therefore should not be overridden are:
 
 ``'docclass'``
diff --git a/sphinx/builders/latex/constants.py b/sphinx/builders/latex/constants.py
index f5e69225d0..3e06761fcb 100644
--- a/sphinx/builders/latex/constants.py
+++ b/sphinx/builders/latex/constants.py
@@ -198,6 +198,9 @@
         'polyglossia':  '',
         'babel':        '\\usepackage{babel}',
         'fontenc':      '\\usepackage{xeCJK}',
+        # sed formatcom=\xeCJKVerbAddon to make xeCJK not add extra spaces in
+        # fancyvrb Verbatim enviroment.
+        'fvset':        '\\fvset{fontsize=\\small,formatcom=\\xeCJKVerbAddon}',
     },
     ('xelatex', 'el'): {
         'fontpkg':      XELATEX_GREEK_DEFAULT_FONTPKG,