diff --git a/Files b/Files
index 490514e94..f9b11063a 100644
--- a/Files
+++ b/Files
@@ -132,7 +132,7 @@ version.c   vision.c    weapon.c    were.c      wield.c     windows.c
 wizard.c    worm.c      worn.c      write.c     zap.c
 
 sys/amiga:
-(files for Amiga versions - untested for 3.6.3)
+(files for Amiga versions - untested for 3.6.4)
 Build.ami     Install.ami   Makefile.agc  Makefile.ami  NetHack.cnf
 amidos.c      amidos.p      amifont.uu    amifont8.uu   amigst.c
 amii.hlp      amimenu.c     amirip.c      amistack.c    amitty.c
@@ -142,12 +142,12 @@ winchar.c     windefs.h     winext.h      winfuncs.c    winkey.c
 winmenu.c     winproto.h    winreq.c      winstr.c      xpm2iff.c
 
 sys/atari:
-(files for Atari version - untested for 3.6.3)
+(files for Atari version - untested for 3.6.4)
 Install.tos   atarifnt.uue  nethack.mnu   setup.g       tos.c
 unx2atar.sed
 
 sys/be:
-(files for BeOS version - untested for 3.6.3)
+(files for BeOS version - untested for 3.6.4)
 README    bemain.c
 
 sys/mac:
@@ -159,7 +159,7 @@ macmenu.c     mactopl.c     mactty.c      macunix.c     macwin.c
 mgetline.c    mmodal.c      mrecover.c    mrecover.hqx  mttymain.c
 
 sys/msdos:
-(files for MSDOS version - tested for 3.6.3 via cross-compile only)
+(files for MSDOS version - tested for 3.6.4 via partial cross-compile only)
 Install.dos             Makefile.BC             Makefile.GCC
 Makefile.MSC            Makefile1.cross         Makefile2.cross
 SCHEMA35.MSC            moveinit.pat            msdos-cross-compile.sh
@@ -175,7 +175,7 @@ vidvga.c
 nhico.uu  nhpif.uu
 
 sys/os2:
-(files for OS/2 version - untested for 3.6.3)
+(files for OS/2 version - untested for 3.6.4)
 Install.os2   Makefile.os2  nhpmico.uu    os2.c
 
 sys/share:
@@ -185,10 +185,10 @@ random.c
 (Berkeley uudecode file, which may be used in build process of any version)
 uudecode.c
 
-(file for MSDOS, OS/2, Amiga, and Atari versions - untested for 3.6.3)
+(file for MSDOS, OS/2, Amiga, and Atari versions - untested for 3.6.4)
 pcmain.c
 
-(file for MSDOS, OS/2, and Atari versions - untested for 3.6.3)
+(file for MSDOS, OS/2, and Atari versions - untested for 3.6.4)
 NetHack.cnf  pctty.c
 
 (file for MSDOS, OS/2, and VMS versions)
@@ -200,10 +200,10 @@ nhlan.c
 (file for VMS version)
 tclib.c
 
-(files for MSDOS and OS/2 versions - untested for 3.6.3)
+(files for MSDOS and OS/2 versions - untested for 3.6.4)
 Makefile.lib  termcap.uu
 
-(files for MSDOS, OS/2 and Atari versions - tested on MSDOS for 3.6.3 via cross-compile only)
+(files for MSDOS, OS/2 and Atari versions - tested on MSDOS for 3.6.4 via partial cross-compile only)
 pcsys.c   pcunix.c
 
 (files for UNIX and Be versions)
@@ -262,7 +262,7 @@ spec_lev.com  sysconf       vmsbuild.com  vmsfiles.c    vmsmail.c
 vmsmain.c     vmsmisc.c     vmstty.c      vmsunix.c
 
 sys/wince:
-(files for Windows CE and PocketPC - untested for 3.6.3)
+(files for Windows CE and PocketPC - untested for 3.6.4)
 Install.ce    bootstrp.mak  celib.c       cesetup.bat   cesound.c
 defaults.nh   keypad.uu     menubar.uu    mhaskyn.c     mhaskyn.h
 mhcmd.c       mhcmd.h       mhcolor.c     mhcolor.h     mhdlg.c
@@ -275,7 +275,7 @@ resource.h    winMS.h       winhack.c     winhack.rc    winhcksp.rc
 winmain.c
 
 sys/wince/ceinc:
-(header files for Windows CE and PocketPC - untested for 3.6.3)
+(header files for Windows CE and PocketPC - untested for 3.6.4)
 assert.h  errno.h   fcntl.h
 
 sys/wince/ceinc/sys:
@@ -343,12 +343,12 @@ cursinit.h  cursinvt.c  cursinvt.h  cursmain.c  cursmesg.c  cursmesg.h
 cursmisc.c  cursmisc.h  cursstat.c  cursstat.h  curswins.c  curswins.h
 
 win/gem:
-(files for GEM versions - untested for 3.6.3)
+(files for GEM versions - untested for 3.6.4)
 Install.gem  bitmfile.c   gem_rsc.uu   gem_rso.uu   gr_rect.c    gr_rect.h
 load_img.c   tile2img.c   title.uu     wingem.c     wingem1.c    xpm2img.c
 
 win/gnome:
-(files for GNOME versions - untested for 3.6.3)
+(files for GNOME versions - untested for 3.6.4)
 README      gn_xpms.h   gnaskstr.c  gnaskstr.h  gnbind.c    gnbind.h
 gnglyph.c   gnglyph.h   gnmain.c    gnmain.h    gnmap.c     gnmap.h
 gnmenu.c    gnmenu.h    gnmesg.c    gnmesg.h    gnomeprv.h  gnopts.c
diff --git a/doc/Guidebook.txt b/doc/Guidebook.txt
index 4e4a4ce3c..bc5989693 100644
--- a/doc/Guidebook.txt
+++ b/doc/Guidebook.txt
@@ -15,7 +15,7 @@
                          Original version - Eric S. Raymond
              (Edited and expanded for 3.6 by Mike Stephenson and others)
 
-                                  December 5, 2019
+                                  December 17, 2019
 
 
 
@@ -6042,6 +6042,9 @@
                NetHack 3.6.3 was released on December  5,  2019  containing
           over 190 bug fixes to NetHack 3.6.2.
 
+               NetHack 3.6.4 was released on December 17, 2019 containing a
+          security fix and a few bug fixes.
+
                The official NetHack web site is maintained by Ken Lorber at
           https://www.nethack.org/.