diff --git a/manual/luatex-lua.tex b/manual/luatex-lua.tex
index 625334c1b8a4e260bad92a2abf3b65ca4d4cfdf7..04dceda64ffc915f1cda57d29b16df8a9c9dbc9b 100644
--- a/manual/luatex-lua.tex
+++ b/manual/luatex-lua.tex
@@ -339,7 +339,7 @@ be done with \type {lfs.attributes}. The additional function \type
 {lfs.shortname} takes a file name and returns its short name on \type {win32}
 platforms. Finally, for non|-|\type {win32} platforms only, we provided \type
 {lfs.readlink} that takes an existing symbolic link as argument and returns its
-name. However, the \type library evolved so we have dropped these in favour of
+name. However, the \type {lfs} library evolved so we have dropped these in favour of
 pure \LUA\ variants. The \type {shortname} helper is obsolete and now just
 returns the name.
 
diff --git a/manual/luatex.pdf b/manual/luatex.pdf
index b044846b7cf0636b8c99b27ffa37670073a48771..7aa4e52431d34a0c053a7adc25260c3cd74350c5 100644
Binary files a/manual/luatex.pdf and b/manual/luatex.pdf differ
diff --git a/source/texk/web2c/luatexdir/NEWS b/source/texk/web2c/luatexdir/NEWS
index 42f85aeb511e00708392e2dbe61a5980f4641ade..b6a77b39f1017acd2e97a0b1bd0a66e56b4c4ab3 100644
--- a/source/texk/web2c/luatexdir/NEWS
+++ b/source/texk/web2c/luatexdir/NEWS
@@ -1,3 +1,13 @@
+==============================================================
+LuaTeX 1.13.1 2021-04-02
+==============================================================
+
+Fixed an unwanted space in btex etex in metapost, introduced 
+after a patch for troff.
+
+
+
+
 ==============================================================
 LuaTeX 1.13.0 2021-03-12
 ==============================================================
diff --git a/source/texk/web2c/luatexdir/luatex.c b/source/texk/web2c/luatexdir/luatex.c
index d7414ef3fd9b617b8c440442b9d5549ac3d79c42..9f2f18c1878df723adffffb6b0bb9af55126da78 100644
--- a/source/texk/web2c/luatexdir/luatex.c
+++ b/source/texk/web2c/luatexdir/luatex.c
@@ -33,8 +33,8 @@
 */
 
 int luatex_version = 113;
-int luatex_revision = '0';
-const char *luatex_version_string = "1.13.0";
+int luatex_revision = '1';
+const char *luatex_version_string = "1.13.1";
 const char *engine_name = my_name;
 
 #include <kpathsea/c-ctype.h>
diff --git a/source/texk/web2c/luatexdir/luatex_svnversion.h b/source/texk/web2c/luatexdir/luatex_svnversion.h
index ef4ef84eb98688fcce4e6013729677e0bd960773..c1c2e210e00293a84c0ff46a466e217612fa3ccb 100644
--- a/source/texk/web2c/luatexdir/luatex_svnversion.h
+++ b/source/texk/web2c/luatexdir/luatex_svnversion.h
@@ -1 +1 @@
-#define luatex_svn_revision 7420
+#define luatex_svn_revision 7428
diff --git a/source/texk/web2c/mplibdir/ChangeLog b/source/texk/web2c/mplibdir/ChangeLog
index 8085a9db296682d2675c235ee854f16a39d6314e..1f6949d76aab01c155f939c04255af143038760f 100644
--- a/source/texk/web2c/mplibdir/ChangeLog
+++ b/source/texk/web2c/mplibdir/ChangeLog
@@ -1,10 +1,12 @@
+2021-04-02  Luigi Scarso  <luigi.scarso@gmail.com>
+	* Revert the patch in mpx_copy_mpto, it was wrong in tex mode. Added a check if in troff mode.
+
 2021-03-23 Karl Berry <karl@tug.org>
     * TL'21.
 
 2020-12-28  Luigi Scarso  <luigi.scarso@gmail.com>
 	* Temp, fix in mpx_copy_mpto, changed || with && to avoid a wrong final %
 
-
 2020-12-27  Luigi Scarso  <luigi.scarso@gmail.com>
 	* Fixed some typos in manual (thank to 胡亚捷 (Hu Yajie) )
 	* Added the undocumented -T option
diff --git a/source/texk/web2c/mplibdir/am/libmplib.am b/source/texk/web2c/mplibdir/am/libmplib.am
index 4b0fc7fd59f027918dc043d39a80e4218e7749c4..24245f5785efaeb7a0b2139a3106e07cfc52c939 100644
--- a/source/texk/web2c/mplibdir/am/libmplib.am
+++ b/source/texk/web2c/mplibdir/am/libmplib.am
@@ -1,6 +1,6 @@
 ## texk/web2c/mplibdir/am/libmplib.am: Makefile fragment for libmplib.
 ##
-## Copyright (C) 2015-2020 Luigi Scarso <tex-live@tug.org>
+## Copyright (C) 2015-2021 Luigi Scarso <tex-live@tug.org>
 ## Copyright (C) 2009-2014 Peter Breitenlohner <tex-live@tug.org>
 ## You may freely use, modify and/or distribute this file.
 
diff --git a/source/texk/web2c/mplibdir/am/mplib.am b/source/texk/web2c/mplibdir/am/mplib.am
index a8b0da6ee2643adf195bc682241fb6aecc1ddf3c..0cfdec7ac3103e2fb44cf161172b9fc878181bd7 100644
--- a/source/texk/web2c/mplibdir/am/mplib.am
+++ b/source/texk/web2c/mplibdir/am/mplib.am
@@ -1,6 +1,6 @@
 ## texk/web2c/mplibdir/am/mplib.am: Makefile fragment for MetaPost.
 ##
-## Copyright 2017-2018 Luigi Scarso <tex-live@tug.org>
+## Copyright 2017-2021 Luigi Scarso <tex-live@tug.org>
 ## Copyright 2009-2015 Peter Breitenlohner <tex-live@tug.org>
 ## You may freely use, modify and/or distribute this file.
 
diff --git a/source/texk/web2c/mplibdir/mpxout.w b/source/texk/web2c/mplibdir/mpxout.w
index f08645a28f0a498192128b1ea659789b09328224..96a1f3d776e43d32f45d926ed3976633ac578d13 100644
--- a/source/texk/web2c/mplibdir/mpxout.w
+++ b/source/texk/web2c/mplibdir/mpxout.w
@@ -564,7 +564,7 @@ static void mpx_copy_mpto (MPX mpx, FILE *outfile, int textype) {
     if (textype == B_TEX) {
       /* put no |%| at end if it's only 1 line total, starting with |%|;
        * this covers the special case |%&format| in a single line. */
-      if (t != s && *t != '%')
+      if ((t != s || *t != '%') && mpx->mode == mpx_tex_mode)
         fprintf(outfile,"%%");
     }
     free(res);