diff --git a/polymer/eduke32/source/lunatic/build.lua b/polymer/eduke32/source/lunatic/build.lua
index 72a6862b1..2607ede08 100644
--- a/polymer/eduke32/source/lunatic/build.lua
+++ b/polymer/eduke32/source/lunatic/build.lua
@@ -5,11 +5,14 @@
 local ffi = require "ffi"
 local io = require "io"
 local bit = require "bit"
+local string = require "string"
+local table = require "table"
 
 local error = error
 local assert = assert
 local print = print
 local setmetatable = setmetatable
+local tostring = tostring
 
 module(...)
 
@@ -130,6 +133,52 @@ local function get_numyaxbunches(map)
     return numbunches
 end
 
+--== sprite canonicalizer ==--
+local function sprite2str(s)
+    local FMT = "%+11d_"
+    -- NOTE: this canonicalization isn't very useful except for debugging
+    -- copy-paste in the editor.
+    -- tostring(s): make sort stable
+    return string.format(FMT:rep(4).."%s", s.x, s.y, s.z, s.ang, tostring(s))
+end
+
+local function canonicalize_sprite_order(map)
+    local numsprites = map.numsprites
+
+    map.spriten2o = {}  -- mapping of new to old sprite index
+
+    if (numsprites == 0) then
+        return
+    end
+
+    local spriteidx = {}
+
+    for i=0,numsprites-1 do  -- 0->1 based indexing
+        spriteidx[i+1] = i
+    end
+
+    table.sort(spriteidx,
+               function(i1, i2)
+                   return sprite2str(map.sprite[i1]) < sprite2str(map.sprite[i2])
+               end)
+
+    -- deep-copied sprite structs
+    local spritedup = {}
+
+    for i=0,numsprites-1 do
+        -- save sorting permutation (0-based -> 0-based)
+        map.spriten2o[i] = assert(spriteidx[i+1])
+
+        -- back up struct
+        spritedup[i] = ffi.new("spritetype")
+        ffi.copy(spritedup[i], map.sprite[i], ffi.sizeof("spritetype"))
+    end
+
+    for i=0,numsprites-1 do  -- do the actual rearrangement
+        map.sprite[i] = spritedup[spriteidx[i+1]]
+    end
+end
+
 --== LOADBOARD ==--
 -- returns:
 --  on failure, nil, errmsg
@@ -144,7 +193,7 @@ end
 --        { x=<num>, y=<num>, z=<num>, ang=<num>, sectnum=<num> },
 --      numbunches = <num>,
 --    }
-function loadboard(filename)
+function loadboard(filename, do_canonicalize_sprite)
     local fh, errmsg = io.open(filename)
 
     if (fh==nil) then
@@ -223,6 +272,11 @@ function loadboard(filename)
     end
     fh:close()
 
+    if (do_canonicalize_sprite) then
+        -- must do this before setting metatable
+        canonicalize_sprite_order(map)
+    end
+
     map.sector = set_secwalspr_mt(map.sector, map.numsectors)
     map.wall = set_secwalspr_mt(map.wall, map.numwalls)
     map.sprite = set_secwalspr_mt(map.sprite, map.numsprites)
diff --git a/polymer/eduke32/source/lunatic/map2text.lua b/polymer/eduke32/source/lunatic/map2text.lua
index a8e654d22..f8d486f91 100755
--- a/polymer/eduke32/source/lunatic/map2text.lua
+++ b/polymer/eduke32/source/lunatic/map2text.lua
@@ -3,10 +3,29 @@
 local B = require("build")
 local string = require("string")
 
-local fn = arg[1]
+local opt, fn
+local do_canonicalize_sprite
+
+if (arg[1] and arg[1]:sub(1,1)=="-") then
+    opt = arg[1]
+    fn = arg[2]
+else
+    fn = arg[1]
+end
+
+if (opt) then
+    if (opt=="-c" or opt=="-C") then
+        -- -C means to canonicalize but without adding the new->old mapping
+        -- comment
+        do_canonicalize_sprite = opt
+    else
+        print("Error: unrecognized option "..opt)
+        return 1
+    end
+end
 
 if (fn==nil) then
-    print("Usage: map2text <somefile.map>")
+    print("Usage: map2text [-c/-C] <somefile.map>")
     return 1
 end
 
@@ -14,7 +33,7 @@ local function printf(fmt, ...)
     print(string.format(fmt, ...))
 end
 
-local map, errmsg = B.loadboard(fn)
+local map, errmsg = B.loadboard(fn, do_canonicalize_sprite)
 if (map == nil) then
     printf("Couldn't load \"%s\": %s", fn, errmsg)
     return 1
@@ -68,13 +87,21 @@ local sprite_members = {
 local function print_members(map, struct, members)
     printf("%s = {", struct)
     for i=0,map["num"..struct.."s"]-1 do
-        printf("[%d]={", i)
+        local comment = ""
+        if (struct=="sprite" and do_canonicalize_sprite=="-c") then
+            comment = "  --"..tostring(map.spriten2o[i])
+        end
+
+        printf("[%d]={%s", i, comment)
+
         for j=1,#members do
             local member = members[j]
             printf("%s = %d", member, map[struct][i][member])
         end
+
         print("}")
     end
+
     print("}")
 end
 
diff --git a/polymer/eduke32/source/lunatic/mapdiff.sh b/polymer/eduke32/source/lunatic/mapdiff.sh
index 0d1df26cf..f3354ae08 100755
--- a/polymer/eduke32/source/lunatic/mapdiff.sh
+++ b/polymer/eduke32/source/lunatic/mapdiff.sh
@@ -1,8 +1,10 @@
 #!/bin/sh
 
-DIFF="git diff --no-index --color-words"
+DIFF="git diff -U2 --no-index --color-words"
 CMD="/usr/bin/env luajit ./map2text.lua"
 
+opt=""
+
 if [ `uname -s` != "Linux" ]; then
     # I think 'tempfile' isn't in POSIX. Feel free to use 'mktemp' or something
     # but absolutely test it before.
@@ -10,16 +12,21 @@ if [ `uname -s` != "Linux" ]; then
     return 1
 fi
 
+if [ "$1" = "-c" -o "$1" = "-C" ]; then
+    opt="$1"
+    shift
+fi
+
 if [ -z "$1" -o -z "$2" ]; then
-    echo "Usage: ./mapdiff.sh <file.map> <file2.map>"
+    echo "Usage: ./mapdiff.sh [-c] <file.map> <file2.map>"
     exit 1
 fi
 
 tf1=`tempfile`
 tf2=`tempfile`
 
-$CMD "$1" > "$tf1"
-$CMD "$2" > "$tf2"
+$CMD $opt "$1" > "$tf1"
+$CMD $opt "$2" > "$tf2"
 
 $DIFF "$tf1" "$tf2"