diff --git a/README.md b/README.md
index d4e9f9c..7daf998 100644
--- a/README.md
+++ b/README.md
@@ -21,6 +21,11 @@ Note: for OSX, if using clang from Xcode 5, you may need to set `CFLAGS` like so
 
     CFLAGS='-stdlib=libc++' pip install pycapnp
 
+If you wish to install using the latest upstream C++ Cap'n Proto:
+
+    pip install --install-option "--libcapnp-url" --install-option "https://github.com/sandstorm-io/capnproto/archive/master.tar.gz" --install-option "--force-bundled-libcapnp" .
+
+
 ## Python Versions
 
 Python 2.6/2.7 are supported as well as Python 3.2+. PyPy 2.1+ is also supported.
diff --git a/buildutils/bundle.py b/buildutils/bundle.py
index 9271036..7a6b446 100644
--- a/buildutils/bundle.py
+++ b/buildutils/bundle.py
@@ -73,19 +73,32 @@ def fetch_archive(savedir, url, fname, force=False):
 # libcapnp
 #-----------------------------------------------------------------------------
 
-def fetch_libcapnp(savedir):
+def fetch_libcapnp(savedir, url=None):
     """download and extract libcapnp"""
+    is_preconfigured = False
+    if url is None:
+        url = libcapnp_url
+        is_preconfigured = True
     dest = pjoin(savedir, 'capnproto-c++')
     if os.path.exists(dest):
         info("already have %s" % dest)
         return
-    fname = fetch_archive(savedir, libcapnp_url, libcapnp)
+    fname = fetch_archive(savedir, url, libcapnp)
     tf = tarfile.open(fname)
     with_version = pjoin(savedir, tf.firstmember.path)
     tf.extractall(savedir)
     tf.close()
     # remove version suffix:
-    shutil.move(with_version, dest)
+    if is_preconfigured:
+        shutil.move(with_version, dest)
+    else:
+        cpp_dir = os.path.join(with_version, 'c++')
+        conf = Popen(['autoreconf', '-i'], cwd=cpp_dir)
+        returncode = conf.wait()
+        if returncode != 0:
+          raise RuntimeError('Autoreconf failed. Make sure autotools are installed on your system.')
+        shutil.move(cpp_dir, dest)
+
 
 def stage_platform_hpp(capnproot):
     """stage platform.hpp into libcapnp sources
@@ -162,4 +175,3 @@ def copy_and_patch_libcapnp(capnp, libcapnp):
         out,err = p.communicate()
         if p.returncode:
             fatal("Could not patch bundled libcapnp install_name: %s"%err, p.returncode)
-
diff --git a/setup.py b/setup.py
index 512a464..6211e04 100644
--- a/setup.py
+++ b/setup.py
@@ -79,6 +79,14 @@ force_cython = "--force-cython" in sys.argv
 if force_cython:
     sys.argv.remove("--force-cython")
     use_cython = True
+libcapnp_url = None
+try:
+    libcapnp_url_index = sys.argv.index("--libcapnp-url")
+    libcapnp_url = sys.argv[libcapnp_url_index + 1]
+    sys.argv.remove("--libcapnp-url")
+    sys.argv.remove(libcapnp_url)
+except:
+    pass
 
 if use_cython:
     from Cython.Distutils import build_ext as build_ext_c
@@ -107,7 +115,7 @@ class build_libcapnp_ext(build_ext_c):
             build_dir = os.path.join(_this_dir, "build")
             if not os.path.exists(build_dir):
                 os.mkdir(build_dir)
-            fetch_libcapnp(bundle_dir)
+            fetch_libcapnp(bundle_dir, libcapnp_url)
 
             build_libcapnp(bundle_dir, build_dir)