diff --git a/build.bat b/build.bat
index 27c32402..87c48afe 100644
--- a/build.bat
+++ b/build.bat
@@ -5,7 +5,7 @@ rmdir /q /s dist
 del /q /f gam-%1-windows.zip
 del /q /f gam-%1-windows-x64.zip
 
-\python27-32\python.exe setup.py py2exe
+c:\python27-32\scripts\pyinstaller -F --distpath=gam gam.py
 xcopy LICENSE gam\
 xcopy whatsnew.txt gam\
 xcopy cacert.pem gam\
@@ -13,7 +13,7 @@ xcopy admin-settings-v1.json gam\
 del gam\w9xpopen.exe
 "%ProgramFiles(x86)%\7-Zip\7z.exe" a -tzip gam-%1-windows.zip gam\ -xr!.svn
 
-\python27\python.exe setup-64.py py2exe
+c:\python27\scripts\pyinstaller -F --distpath=gam-64 gam.py
 xcopy LICENSE gam-64\
 xcopy whatsnew.txt gam-64\
 xcopy cacert.pem gam-64\