diff --git a/.appveyor.yml b/.appveyor.yml
index 7305778..7e50cde 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -1,15 +1,13 @@
 build: false
 
 platform:
-  # TODO - get 64 bit build working
-  # - x64
   - x86
 
 install:
   - git submodule update --init --recursive
-  - IF "%PLATFORM%" == "x86" set PYTHON=C:\Python37
-  - IF "%PLATFORM%" == "x64" set PYTHON=C:\Python37-x64
+  - IF "%PLATFORM%" == "x86" set PATH=C:\Python37;%PATH%
+  - IF "%PLATFORM%" == "x64" set PATH=C:\Python37-x64;%PATH%
 
 test_script:
   - script\fetch-fixtures.cmd
-  - "%PYTHON%\\python.exe setup.py test"
+  - python.exe setup.py --quiet test
diff --git a/setup.py b/setup.py
index 4492236..21f1b2c 100644
--- a/setup.py
+++ b/setup.py
@@ -1,47 +1,48 @@
 """
 Py-Tree-sitter
 """
 
 
+import platform
 from setuptools import setup, Extension
 
 
 setup(
     name = "tree_sitter",
     version = "0.0.4",
     maintainer = "Max Brunsfeld",
     maintainer_email = "maxbrunsfeld@gmail.com",
     author = "Max Brunsfeld",
     author_email = "maxbrunsfeld@gmail.com",
     url = "https://github.com/tree-sitter/py-tree-sitter",
     license = "MIT",
     platforms = ["any"],
     python_requires = ">=3.3",
     description = "Python bindings to the Tree-sitter parsing library",
     classifiers = [
         "License :: OSI Approved :: MIT License",
         "Topic :: Software Development :: Compilers",
         "Topic :: Text Processing :: Linguistic",
     ],
     packages = ['tree_sitter'],
     ext_modules = [
         Extension(
             "tree_sitter_binding",
             [
                 "tree_sitter/core/lib/src/lib.c",
                 "tree_sitter/binding.c",
             ],
             include_dirs = [
                 "tree_sitter/core/lib/include",
                 "tree_sitter/core/lib/utf8proc",
             ],
-            extra_compile_args = [
-                "-std=c99",
-            ],
+            extra_compile_args = (
+                ['-std=c99'] if platform.system() != 'Windows' else None
+            )
         )
     ],
     project_urls = {
         'Source': 'https://github.com/tree-sitter/py-tree-sitter',
         'Documentation': 'http://initd.org/psycopg/docs/',
     }
 )
diff --git a/tree_sitter/__init__.py b/tree_sitter/__init__.py
index 1749e04..3503121 100644
--- a/tree_sitter/__init__.py
+++ b/tree_sitter/__init__.py
@@ -1,75 +1,79 @@
 from ctypes import cdll, c_void_p
 from ctypes.util import find_library
 from distutils.ccompiler import new_compiler
 from tempfile import TemporaryDirectory
 from tree_sitter_binding import Parser
 import os.path as path
+import platform
 
 
 class Language:
     def build_library(output_path, repo_paths):
         """
         Build a dynamic library at the given path, based on the parser
         repositories at the given paths.
 
         Returns `True` if the dynamic library was compiled and `False` if
         the library already existed and was modified more recently than
         any of the source files.
         """
         output_mtime = 0
         if path.exists(output_path):
             output_mtime = path.getmtime(output_path)
 
         if len(repo_paths) == 0:
             raise ValueError('Must provide at least one language folder')
 
         cpp = False
         source_paths = []
         source_mtimes = [path.getmtime(__file__)]
         for repo_path in repo_paths:
             src_path = path.join(repo_path, 'src')
             source_paths.append(path.join(src_path, "parser.c"))
             source_mtimes.append(path.getmtime(source_paths[-1]))
             if path.exists(path.join(src_path, "scanner.cc")):
                 cpp = True
                 source_paths.append(path.join(src_path, "scanner.cc"))
                 source_mtimes.append(path.getmtime(source_paths[-1]))
             elif path.exists(path.join(src_path, "scanner.c")):
                 source_paths.append(path.join(src_path, "scanner.c"))
                 source_mtimes.append(path.getmtime(source_paths[-1]))
 
         compiler = new_compiler()
         if cpp:
             if find_library('c++'):
                 compiler.add_library('c++')
             elif find_library('stdc++'):
                 compiler.add_library('stdc++')
 
         if max(source_mtimes) > output_mtime:
             with TemporaryDirectory(suffix = 'tree_sitter_language') as dir:
                 object_paths = []
                 for source_path in source_paths:
-                    flags = ['-fPIC']
-                    if source_path.endswith('.c'):
-                        flags.append('-std=c99')
+                    if platform.system() == 'Windows':
+                        flags = None
+                    else:
+                        flags = ['-fPIC']
+                        if source_path.endswith('.c'):
+                            flags.append('-std=c99')
                     object_paths.append(compiler.compile(
                         [source_path],
                         output_dir = dir,
                         include_dirs = [path.dirname(source_path)],
                         extra_preargs = flags
                     )[0])
                 compiler.link_shared_object(object_paths, output_path)
             return True
         else:
             return False
 
     def __init__(self, library_path, name):
         """
         Load the language with the given name from the dynamic library
         at the given path.
         """
         self.name = name
         self.lib = cdll.LoadLibrary(library_path)
         language_function = getattr(self.lib, "tree_sitter_%s" % name)
         language_function.restype = c_void_p
         self.language_id = language_function()