diff --git a/install.sh b/install.sh
index 90b8a0a..22bfb13 100755
--- a/install.sh
+++ b/install.sh
@@ -1,11 +1,11 @@
 #!/bin/sh
-ENGINE="$(which luametatex)"
+ENGINE="$(which luametatex$EXE_EXT)"
 ENGINE_DIR="$(dirname "$ENGINE")"
 REPO="$(pwd)"
 cd "$(dirname "$ENGINE")"
-ln -s luametatex luametaplain
-ln -s luametatex luametalatex
-ln -s luametatex luametalatex-dev
+ln -s luametatex$EXE_EXT luametaplain$EXE_EXT
+ln -s luametatex$EXE_EXT luametalatex$EXE_EXT
+ln -s luametatex$EXE_EXT luametalatex-dev$EXE_EXT
 ln -s "$REPO/luametaplain.lua" .
 ln -s "$REPO/luametalatex.lua" .
 ln -s "$REPO/luametalatex-dev.lua" .
diff --git a/luametalatex-callbacks.lua b/luametalatex-callbacks.lua
index 0f05ee6..0af8ffc 100644
--- a/luametalatex-callbacks.lua
+++ b/luametalatex-callbacks.lua
@@ -40,7 +40,7 @@ do
 end
 -- callback_register('read_data_file', function(name) error[[TODO]]return kpse.find_file(name, 'tex', true) end)
 callback_register('open_data_file', function(name)
-  local f = io.open(name)
+  local f = io.open(name, 'r')
   return setmetatable({
     reader = function()
       local line = f:read()
diff --git a/luametalatex-font-enc.lua b/luametalatex-font-enc.lua
index 56ac8e3..3ff9ed4 100644
--- a/luametalatex-font-enc.lua
+++ b/luametalatex-font-enc.lua
@@ -5,7 +5,7 @@ local lname = '/' * name / 1
 local namearray = lpeg.Ct('['*white^0*lpeg.Cg(lname*white^0, 0)^-1*(lname*white^0)^0*']')
 local encfile = white^0*lname*white^0*namearray*white^0*'def'*white^0*-1
 return function(filename)
-  local file = io.open(filename)
+  local file = io.open(filename, 'r')
   local name, encoding = encfile:match(file:read'a')
   file:close()
   return encoding, name
diff --git a/luametalatex-font-t1.lua b/luametalatex-font-t1.lua
index 993bc21..6edb07d 100644
--- a/luametalatex-font-t1.lua
+++ b/luametalatex-font-t1.lua
@@ -119,7 +119,7 @@ local function parse_maintable(offset, str)
 end
 
 return function(filename)
-  local file = io.open(filename)
+  local file = io.open(filename, 'rb')
   local _, length = string.unpack("<I2I4", file:read(6))
   local preface = file:read(length)
   _, length = string.unpack("<I2I4", file:read(6))
diff --git a/luametalatex-font-tfm.lua b/luametalatex-font-tfm.lua
index 5c6dbd3..cf89a21 100644
--- a/luametalatex-font-tfm.lua
+++ b/luametalatex-font-tfm.lua
@@ -143,7 +143,7 @@ local basename = ((1-lpeg.S'\\/')^0*lpeg.S'\\/')^0*lpeg.C((1-lpeg.P'.tfm'*-1)^0)
 return function(name, size)
   local filename = kpse.find_file(name, 'tfm', true)
   if not filename then return end
-  local f = io.open(filename)
+  local f = io.open(filename, 'rb')
   if not f then return end
   local buf = f:read'*a'
   f:close()
diff --git a/luametalatex-font-vf.lua b/luametalatex-font-vf.lua
index 4d5c4b4..4fc3beb 100644
--- a/luametalatex-font-vf.lua
+++ b/luametalatex-font-vf.lua
@@ -168,7 +168,7 @@ local basename = ((1-lpeg.S'\\/')^0*lpeg.S'\\/')^0*lpeg.C((1-lpeg.P'.tfm'*-1)^0)
 return function(name, size, must_exist)
   local filename = kpse.find_file(name, 'vf', must_exist)
   if not filename then return end
-  local f = io.open(filename)
+  local f = io.open(filename, 'rb')
   if not f then return end
   local buf = f:read'*a'
   f:close()
diff --git a/luametalatex-pdf-font-cff.lua b/luametalatex-pdf-font-cff.lua
index f6db785..1c47629 100644
--- a/luametalatex-pdf-font-cff.lua
+++ b/luametalatex-pdf-font-cff.lua
@@ -581,7 +581,7 @@ end
 -- file:close()
 -- io.open(arg[3], 'w'):write(myfunc(buf, 1, 1, nil, {{3}, {200}, {1000}, {1329}, {1330}, {1331}})):close()
 return function(filename, fontid, encoding) return function(fontdir, usedcids)
-  local file = io.open(filename)
+  local file = io.open(filename, 'rb')
   local buf = file:read'a'
   local i = 1
   file:close()
diff --git a/luametalatex-pdf-font-map.lua b/luametalatex-pdf-font-map.lua
index 06550f6..4c27d38 100644
--- a/luametalatex-pdf-font-map.lua
+++ b/luametalatex-pdf-font-map.lua
@@ -38,7 +38,7 @@ local function mapfile(filename, operator)
   if not operator then
     operator, filename = optoperator:match(filename)
   end
-  local file = io.open(kpse.find_file(filename, 'map'))
+  local file = io.open(kpse.find_file(filename, 'map'), 'r')
   for line in file:lines() do mapline(line, operator) end
   file:close()
 end
diff --git a/luametalatex-pdf-font-ttf.lua b/luametalatex-pdf-font-ttf.lua
index c630fc6..d8417c9 100644
--- a/luametalatex-pdf-font-ttf.lua
+++ b/luametalatex-pdf-font-ttf.lua
@@ -68,7 +68,7 @@ local function readpostnames(buf, i, usedcids, encoding)
   return newusedcids
 end
 return function(filename, fontid, reencode)
-  local file = io.open(filename)
+  local file = io.open(filename, 'rb')
   local buf = file:read'a'
   file:close()
   local magic, tables = sfnt.parse(buf, 1, fontid)
diff --git a/luametalatex-pdf-image-png.lua b/luametalatex-pdf-image-png.lua
index 0a54e7b..500a557 100644
--- a/luametalatex-pdf-image-png.lua
+++ b/luametalatex-pdf-image-png.lua
@@ -204,7 +204,7 @@ end
 local png_functions = {}
 
 function png_functions.scan(img)
-  local file = io.open(img.filepath)
+  local file = io.open(img.filepath, 'rb')
   if not file then
     error[[PDF image could not be opened.]]
   end
@@ -228,7 +228,7 @@ local intents = {[0]=
 }
 local function srgb_lookup(pfile, intent)
   if not srgb_colorspace then
-    local f = io.open(kpse.find_file'sRGB.icc.zlib')
+    local f = io.open(kpse.find_file'sRGB.icc.zlib', 'rb')
     local profile = f:read'a'
     f:close()
     local objnum = pfile:stream(nil, '/Filter/FlateDecode/N ' .. tostring(colortype & 2 == 2 and '3' or '1'), t.iCCP, nil, true)
@@ -259,7 +259,7 @@ local function rawimage(t, content)
 end
 
 function png_functions.write(pfile, img)
-  local file = io.open(img.filepath)
+  local file = io.open(img.filepath, 'rb')
   if not file then
     error[[PDF image could not be opened.]]
   end
diff --git a/luametalatex-pdf.lua b/luametalatex-pdf.lua
index 074ef9e..90c864e 100644
--- a/luametalatex-pdf.lua
+++ b/luametalatex-pdf.lua
@@ -23,7 +23,7 @@ local function stream(pdf, num, dict, content, isfile, raw)
   end
   pdf[num] = {offset = pdf.file:seek()}
   if isfile then
-    local f = io.open(content)
+    local f = io.open(content, 'rb')
     content = f:read'a'
     f:close()
   end
@@ -56,7 +56,7 @@ local function indirect(pdf, num, content, isfile, objstream)
     error[[Invalid object]]
   end
   if isfile then
-    local f = io.open(content)
+    local f = io.open(content, 'rb')
     content = f:read'a'
     f:close()
   end
@@ -165,7 +165,7 @@ local pdfmeta = {
 }
 pdfmeta.__index = pdfmeta
 local function open(filename)
-  local file = io.open(filename, 'w')
+  local file = io.open(filename, 'wb')
   file:write"%PDF-X.X\n%🖋\n"
   return setmetatable({file = file, version = '1.7', [0] = 0, pages = {}, objstream = {}}, pdfmeta)
 end