diff --git a/prepare.py b/prepare.py
index fd47b66a6..9383bb81d 100755
--- a/prepare.py
+++ b/prepare.py
@@ -47,6 +47,8 @@ class DesktopTarget(prepare.Target):
         if platform.system() == 'Windows':
             current_path = current_path.replace('\\', '/')
         self.config_file = 'configs/config-desktop.cmake'
+        if platform.system() == 'Windows':
+            self.generator = 'Visual Studio 12 2013'
         self.additional_args = [
             '-DCMAKE_INSTALL_MESSAGE=LAZY',
             '-DLINPHONE_BUILDER_EXTERNAL_SOURCE_PATH=' +
@@ -162,7 +164,7 @@ def main(argv=None):
     argparser.add_argument(
         '-f', '--force', help="Force preparation, even if working directory already exist.", action='store_true')
     argparser.add_argument(
-        '-G', '--generator', help="CMake build system generator (default: Unix Makefiles, use cmake -h to get the complete list).", default='Unix Makefiles', dest='generator')
+        '-G', '--generator', help="CMake build system generator (default: let CMake choose, use cmake -h to get the complete list).", default=None, dest='generator')
     argparser.add_argument(
         '-L', '--list-cmake-variables', help="List non-advanced CMake cache variables.", action='store_true', dest='list_cmake_variables')
     argparser.add_argument(
@@ -178,7 +180,6 @@ def main(argv=None):
 
     args, additional_args = argparser.parse_known_args()
 
-    additional_args += ["-G", args.generator]
     additional_args += ["-DLINPHONE_BUILDER_GROUP_EXTERNAL_SOURCE_PATH_BUILDERS=YES"]
 
     if args.only_submodules:
@@ -225,6 +226,9 @@ def main(argv=None):
         target = PythonRaspberryTarget()
     else:
         target = DesktopTarget()
+    if args.generator is not None:
+        target.generator = args.generator
+
     if args.clean or args.veryclean:
         if args.veryclean:
             target.veryclean()
@@ -240,18 +244,18 @@ def main(argv=None):
                 retcode = 0
             return retcode
         # only generated makefile if we are using Ninja or Makefile
-        if args.generator.endswith('Ninja'):
+        if target.generator.endswith('Ninja'):
             if not check_is_installed("ninja", "it"):
                 return 1
             generate_makefile('ninja -C')
             info("You can now run 'make' to build.")
-        elif args.generator.endswith("Unix Makefiles"):
+        elif target.generator.endswith("Unix Makefiles"):
             generate_makefile('$(MAKE) -C')
             info("You can now run 'make' to build.")
-        elif args.generator == "Xcode":
+        elif target.generator == "Xcode":
             info("You can now open Xcode project with: open WORK/cmake/Project.xcodeproj")
         else:
-            warning("Not generating meta-makefile for generator {}.".format(args.generator))
+            warning("Not generating meta-makefile for generator {}.".format(target.generator))
 
     return 0