diff --git a/hgext/convert/common.py b/hgext/convert/common.py
--- a/hgext/convert/common.py
+++ b/hgext/convert/common.py
@@ -476,7 +476,7 @@ class mapfile(dict):
                 raise error.Abort(
                     _('could not open map file %r: %s') %
                     (self.path, encoding.strtolocal(err.strerror)))
-        self.fp.write('%s %s\n' % (key, value))
+        self.fp.write(util.tonativeeol('%s %s\n' % (key, value)))
         self.fp.flush()
         super(mapfile, self).__setitem__(key, value)
 
diff --git a/hgext/convert/convcmd.py b/hgext/convert/convcmd.py
--- a/hgext/convert/convcmd.py
+++ b/hgext/convert/convcmd.py
@@ -411,7 +411,8 @@ class converter(object):
             self.ui.status(_('writing author map file %s\n') % authorfile)
             ofile = open(authorfile, 'wb+')
             for author in self.authors:
-                ofile.write("%s=%s\n" % (author, self.authors[author]))
+                ofile.write(util.tonativeeol("%s=%s\n"
+                                             % (author, self.authors[author])))
             ofile.close()
 
     def readauthormap(self, authorfile):
diff --git a/hgext/convert/hg.py b/hgext/convert/hg.py
--- a/hgext/convert/hg.py
+++ b/hgext/convert/hg.py
@@ -626,7 +626,7 @@ class mercurial_source(common.converter_
     def converted(self, rev, destrev):
         if self.convertfp is None:
             self.convertfp = open(self.repo.vfs.join('shamap'), 'ab')
-        self.convertfp.write('%s %s\n' % (destrev, rev))
+        self.convertfp.write(util.tonativeeol('%s %s\n' % (destrev, rev)))
         self.convertfp.flush()
 
     def before(self):
diff --git a/hgext/convert/subversion.py b/hgext/convert/subversion.py
--- a/hgext/convert/subversion.py
+++ b/hgext/convert/subversion.py
@@ -640,7 +640,8 @@ class svn_source(converter_source):
         if self.convertfp is None:
             self.convertfp = open(os.path.join(self.wc, '.svn', 'hg-shamap'),
                                   'ab')
-        self.convertfp.write('%s %d\n' % (destrev, self.revnum(rev)))
+        self.convertfp.write(util.tonativeeol('%s %d\n'
+                                              % (destrev, self.revnum(rev))))
         self.convertfp.flush()
 
     def revid(self, revnum, module=None):
@@ -1309,7 +1310,7 @@ class svn_sink(converter_sink, commandli
 
         fd, messagefile = tempfile.mkstemp(prefix='hg-convert-')
         fp = os.fdopen(fd, pycompat.sysstr('wb'))
-        fp.write(commit.desc)
+        fp.write(util.tonativeeol(commit.desc))
         fp.close()
         try:
             output = self.run0('commit',