diff -Naur borgbackup-1.1.11.orig/setup.cfg borgbackup-1.1.11/setup.cfg
--- borgbackup-1.1.11.orig/setup.cfg	2020-03-07 18:44:15.000000000 -0500
+++ borgbackup-1.1.11/setup.cfg	2020-03-11 10:28:25.168481822 -0400
@@ -6,7 +6,7 @@
 	F401,F405,F811,
 	W504
 max-line-length = 255
-exclude = build,dist,.git,.idea,.cache,.tox,docs/conf.py,src/borg/algorithms/msgpack
+exclude = build,dist,.git,.idea,.cache,.tox,docs/conf.py
 
 [egg_info]
 tag_build = 
diff -Naur borgbackup-1.1.11.orig/setup.py borgbackup-1.1.11/setup.py
--- borgbackup-1.1.11.orig/setup.py	2020-03-07 18:32:06.000000000 -0500
+++ borgbackup-1.1.11/setup.py	2020-03-11 10:28:15.568759338 -0400
@@ -25,8 +25,6 @@
 # True: use the shared libb2 from the system, False: use the bundled blake2 code
 prefer_system_libb2 = True
 
-# prefer_system_msgpack is another option, but you need to set it in src/borg/helpers.py.
-
 min_python = (3, 4)
 my_python = sys.version_info
 
@@ -79,8 +77,6 @@
 platform_syncfilerange_source = 'src/borg/platform/syncfilerange.pyx'
 platform_darwin_source = 'src/borg/platform/darwin.pyx'
 platform_freebsd_source = 'src/borg/platform/freebsd.pyx'
-msgpack_packer_source = 'src/borg/algorithms/msgpack/_packer.pyx'
-msgpack_unpacker_source = 'src/borg/algorithms/msgpack/_unpacker.pyx'
 
 cython_c_sources = [
     # these .pyx will get compiled to .c
@@ -98,12 +94,6 @@
     platform_darwin_source,
 ]
 
-cython_cpp_sources = [
-    # these .pyx will get compiled to .cpp
-    msgpack_packer_source,
-    msgpack_unpacker_source,
-]
-
 try:
     from Cython.Distutils import build_ext
     import Cython.Compiler.Main as cython_compiler
@@ -133,8 +123,6 @@
                 'src/borg/platform/syncfilerange.c',
                 'src/borg/platform/freebsd.c',
                 'src/borg/platform/darwin.c',
-                'src/borg/algorithms/msgpack/_packer.cpp',
-                'src/borg/algorithms/msgpack/_unpacker.cpp',
             ])
             super().make_distribution()
 
@@ -155,14 +143,12 @@
     platform_freebsd_source = platform_freebsd_source.replace('.pyx', '.c')
     platform_darwin_source = platform_darwin_source.replace('.pyx', '.c')
 
-    msgpack_packer_source = msgpack_packer_source.replace('.pyx', '.cpp')
-    msgpack_unpacker_source = msgpack_unpacker_source.replace('.pyx', '.cpp')
 
     from distutils.command.build_ext import build_ext
     if not on_rtd and not all(os.path.exists(path) for path in [
         compress_source, crypto_ll_source, chunker_source, hashindex_source, item_source, checksums_source,
         platform_posix_source, platform_linux_source, platform_syncfilerange_source, platform_freebsd_source, platform_darwin_source,
-        msgpack_packer_source, msgpack_unpacker_source]):
+        ]):
         raise ImportError('The GIT version of Borg needs Cython. Install Cython or use a released version.')
 
 
@@ -805,26 +791,7 @@
                                                system_prefix=libb2_prefix, system=libb2_system,
                                                **crypto_ext_kwargs)
 
-    msgpack_endian = '__BIG_ENDIAN__' if (sys.byteorder == 'big') else '__LITTLE_ENDIAN__'
-    msgpack_macros = [(msgpack_endian, '1')]
-    msgpack_packer_ext_kwargs = dict(
-        sources=[msgpack_packer_source],
-        include_dirs=include_dirs,
-        library_dirs=library_dirs,
-        define_macros=msgpack_macros,
-        language='c++',
-    )
-    msgpack_unpacker_ext_kwargs = dict(
-        sources=[msgpack_unpacker_source],
-        include_dirs=include_dirs,
-        library_dirs=library_dirs,
-        define_macros=msgpack_macros,
-        language='c++',
-    )
-
     ext_modules += [
-        Extension('borg.algorithms.msgpack._packer', **msgpack_packer_ext_kwargs),
-        Extension('borg.algorithms.msgpack._unpacker', **msgpack_unpacker_ext_kwargs),
         Extension('borg.compress', **compress_ext_kwargs),
         Extension('borg.crypto.low_level', **crypto_ext_kwargs),
         Extension('borg.hashindex', [hashindex_source]),
diff -Naur borgbackup-1.1.11.orig/src/borg/helpers.py borgbackup-1.1.11/src/borg/helpers.py
--- borgbackup-1.1.11.orig/src/borg/helpers.py	2020-03-07 18:32:06.000000000 -0500
+++ borgbackup-1.1.11/src/borg/helpers.py	2020-03-11 10:28:42.519980213 -0400
@@ -55,7 +55,7 @@
 #   any feedback related to issues caused by this will be ignored.
 # - especially, it is known that msgpack 0.6.x does NOT work for borg 1.1.x.
 
-prefer_system_msgpack = False
+prefer_system_msgpack = True
 
 try:
     if prefer_system_msgpack: