--- a/watchman/python/setup.py
+++ b/watchman/python/setup.py
@@ -13,30 +13,10 @@ try:
 except ImportError:
     from distutils.core import Extension, setup
 
-watchman_src_dir = os.environ.get("CMAKE_CURRENT_SOURCE_DIR")
-if watchman_src_dir is None:
-    watchman_src_dir = os.path.join(os.path.dirname(os.path.realpath(__file__)), "..")
-
-# Setuptools is very picky about the path on Windows. They have to be relative
-# paths, and on Windows that means we have to be on the same drive as the source
-# files. Otherwise it is impossible to obtain a relative path across different
-# drives. However this has an implication that we will not be able to build this
-# package outside the repository. Not great but it works.
-py_dir = os.path.join(watchman_src_dir, "watchman", "python")
-if os.name == "nt":
-    os.chdir(py_dir)
-    py_dir = os.path.relpath(py_dir)
-
-
-def srcs(names):
-    """transform a list of sources to be relative to py_dir"""
-    return ["%s/%s" % (py_dir, n) for n in names]
-
 
 setup(
     name="pywatchman",
     version="1.4.1",
-    package_dir={"": py_dir},
     description="Watchman client for python",
     author="Wez Furlong, Rain",
     author_email="wez@fb.com",
@@ -50,7 +30,7 @@ setup(
     ext_modules=[
         Extension(
             "pywatchman.bser",
-            sources=srcs(["pywatchman/bsermodule.c", "pywatchman/bser.c"]),
+            sources=["pywatchman/bsermodule.c", "pywatchman/bser.c"],
         )
     ],
     platforms="Platform Independent",
@@ -68,12 +48,10 @@ setup(
         "Programming Language :: Python :: 3.6",
     ],
     zip_safe=True,
-    scripts=srcs(
-        [
+    scripts=[
             "bin/watchman-make",
             "bin/watchman-wait",
             "bin/watchman-replicate-subscription",
-        ]
-    ),
+    ],
     test_suite="tests",
 )
--- a/watchman/python/tests/tests.py
+++ b/watchman/python/tests/tests.py
@@ -28,13 +28,6 @@ from pywatchman import (
 )
 
 
-if os.path.basename(bser.__file__) == "pybser.py":
-    raise Exception(
-        "bser module resolved to pybser! Something is broken in your build. __file__={!r}, sys.path={!r}".format(
-            bser.__file__, sys.path
-        )
-    )
-
 PILE_OF_POO = "\U0001F4A9"
 NON_UTF8_STRING = b"\xff\xff\xff"