diff --git a/.gitmodules b/.gitmodules
index e20bf844..4d2c27e1 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -4,3 +4,6 @@
 [submodule "pyffi/formats/kfm/kfmxml"]
 	path = pyffi/formats/kfm/kfmxml
 	url = git://niftools.git.sourceforge.net/gitroot/niftools/kfmxml
+[submodule "external"]
+	path = external
+	url = git://github.com/amorilia/pyffi-external.git
diff --git a/external b/external
new file mode 160000
index 00000000..f3318554
--- /dev/null
+++ b/external
@@ -0,0 +1 @@
+Subproject commit f331855444e5397270dc9525a8b8d7474fe79546
diff --git a/win-install/pyffi.nsh b/win-install/pyffi.nsh
index 313fe362..4b13647f 100644
--- a/win-install/pyffi.nsh
+++ b/win-install/pyffi.nsh
@@ -361,11 +361,13 @@ legacykeys_end_${label}:
   File /oname=oblivion_optimize.ini.tmp "${MISC_SRCDIR}\utilities\toaster\oblivion_optimize.ini"
   File /oname=unpack_rockstar_dir_img.bat.tmp "${MISC_SRCDIR}\utilities\toaster\unpack_rockstar_dir_img.bat"
   File /oname=pack_rockstar_dir_img.bat.tmp "${MISC_SRCDIR}\utilities\toaster\pack_rockstar_dir_img.bat"
+  File /oname=make_patch.bat.tmp "${MISC_SRCDIR}\external\make_patch.bat"
+  File /oname=apply_patch.bat.tmp "${MISC_SRCDIR}\external\apply_patch.bat"
+  File "${MISC_SRCDIR}\external\xdelta3.0z.x86-32.exe"
 
   CreateDirectory "$INSTDIR\utilities\toaster\in"
   CreateDirectory "$INSTDIR\utilities\toaster\out"
-  ; XXX not yet used
-  ;CreateDirectory "$INSTDIR\utilities\toaster\patches"
+  CreateDirectory "$INSTDIR\utilities\toaster\patches"
   CreateDirectory "$INSTDIR\utilities\toaster\archive_in"
   CreateDirectory "$INSTDIR\utilities\toaster\archive_out"
 
@@ -386,6 +388,14 @@ legacykeys_end_${label}:
   Push "$INSTDIR\utilities\toaster\pack_rockstar_dir_img.bat.tmp"
   Push "$INSTDIR\utilities\toaster\pack_rockstar_dir_img.bat"
   Call unix2dos
+  Delete "$INSTDIR\utilities\toaster\make_patch.bat"
+  Push "$INSTDIR\utilities\toaster\make_patch.bat.tmp"
+  Push "$INSTDIR\utilities\toaster\make_patch.bat"
+  Call unix2dos
+  Delete "$INSTDIR\utilities\toaster\apply_patch.bat"
+  Push "$INSTDIR\utilities\toaster\apply_patch.bat.tmp"
+  Push "$INSTDIR\utilities\toaster\apply_patch.bat"
+  Call unix2dos
 
   ; Install shortcuts
   CreateDirectory "$SMPROGRAMS\PyFFI\"