diff --git a/Lib/fontTools/misc/xmlWriter.py b/Lib/fontTools/misc/xmlWriter.py
index c846f4141..ddc2fdb3e 100644
--- a/Lib/fontTools/misc/xmlWriter.py
+++ b/Lib/fontTools/misc/xmlWriter.py
@@ -4,7 +4,6 @@ from fontTools.misc.py23 import byteord, strjoin, tobytes, tostr
 import sys
 import os
 import string
-import warnings
 
 INDENT = "  "
 
@@ -38,12 +37,10 @@ class XMLWriter(object):
 			self.file.write('')
 			self.totype = tostr
 		self.indentwhite = self.totype(indentwhite)
-		if newlinestr != "\n":
-			warnings.warn(
-				'Setting "newlinestr" is deprecated and will be ignored.',
-				DeprecationWarning,
-			)
-		self.newlinestr = self.totype("\n")
+		if newlinestr is None:
+			self.newlinestr = self.totype(os.linesep)
+		else:
+			self.newlinestr = self.totype(newlinestr)
 		self.indentlevel = 0
 		self.stack = []
 		self.needindent = 1
diff --git a/Lib/fontTools/ttLib/tables/_g_l_y_f.py b/Lib/fontTools/ttLib/tables/_g_l_y_f.py
index 51ea85105..e3bbddb9c 100644
--- a/Lib/fontTools/ttLib/tables/_g_l_y_f.py
+++ b/Lib/fontTools/ttLib/tables/_g_l_y_f.py
@@ -159,7 +159,8 @@ class table__g_l_y_f(DefaultTable.DefaultTable):
 						suffix=ext)
 					existingGlyphFiles.add(glyphPath.lower())
 					glyphWriter = xmlWriter.XMLWriter(
-						glyphPath, idlefunc=writer.idlefunc)
+						glyphPath, idlefunc=writer.idlefunc,
+						newlinestr=writer.newlinestr)
 					glyphWriter.begintag("ttFont", ttLibVersion=version)
 					glyphWriter.newline()
 					glyphWriter.begintag("glyf")
diff --git a/Lib/fontTools/ttLib/ttFont.py b/Lib/fontTools/ttLib/ttFont.py
index ba58e58d9..5ccd182cd 100644
--- a/Lib/fontTools/ttLib/ttFont.py
+++ b/Lib/fontTools/ttLib/ttFont.py
@@ -271,7 +271,8 @@ class TTFont(object):
 			tag = tables[i]
 			if splitTables:
 				tablePath = fileNameTemplate % tagToIdentifier(tag)
-				tableWriter = xmlWriter.XMLWriter(tablePath)
+				tableWriter = xmlWriter.XMLWriter(tablePath,
+						newlinestr=writer.newlinestr)
 				tableWriter.begintag("ttFont", ttLibVersion=version)
 				tableWriter.newline()
 				tableWriter.newline()
diff --git a/Tests/misc/xmlWriter_test.py b/Tests/misc/xmlWriter_test.py
index e1b92894a..7b9894c66 100644
--- a/Tests/misc/xmlWriter_test.py
+++ b/Tests/misc/xmlWriter_test.py
@@ -115,7 +115,7 @@ class TestXMLWriter(unittest.TestCase):
 			writer.write("world")
 			writer.newline()
 
-			linesep = tobytes('\n')
+			linesep = tobytes(os.linesep) if nls is None else tobytes(nls)
 
 			self.assertEqual(
 				header + linesep + b"hello" + linesep + b"world" + linesep,
diff --git a/Tests/ttLib/tables/_n_a_m_e_test.py b/Tests/ttLib/tables/_n_a_m_e_test.py
index 196904077..8e8297049 100644
--- a/Tests/ttLib/tables/_n_a_m_e_test.py
+++ b/Tests/ttLib/tables/_n_a_m_e_test.py
@@ -354,7 +354,7 @@ class NameRecordTest(unittest.TestCase):
 		writer = XMLWriter(BytesIO())
 		name.toXML(writer, ttFont=None)
 		xml = writer.file.getvalue().decode("utf_8").strip()
-		return xml.split("\n")[1:]
+		return xml.split(writer.newlinestr.decode("utf_8"))[1:]
 
 	def test_toXML_utf16be(self):
 		name = makeName("Foo Bold", 111, 0, 2, 7)