nfcpy: "Symbol not found"?

I've install nfcpy via pip, but am struggling to set it up. While running in the python shell, the following error comes up:

>>> import nfc
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/site-packages/nfc/__init__.py", line 28, in <module>
    from clf import ContactlessFrontend
  File "/usr/local/lib/python2.7/site-packages/nfc/clf/__init__.py", line 34, in <module>
    import nfc.llcp
  File "/usr/local/lib/python2.7/site-packages/nfc/llcp/__init__.py", line 31, in <module>
    from llc import LOGICAL_DATA_LINK, DATA_LINK_CONNECTION
  File "/usr/local/lib/python2.7/site-packages/nfc/llcp/llc.py", line 41, in <module>
    from . import sec
  File "/usr/local/lib/python2.7/site-packages/nfc/llcp/sec.py", line 490, in <module>
    OpenSSL = OpenSSLWrapper(libcrypto)
  File "/usr/local/lib/python2.7/site-packages/nfc/llcp/sec.py", line 183, in __init__
    self.crypto.EC_KEY_set_public_key_affine_coordinates.restype = c_int
  File "/usr/local/Cellar/python/2.7.10/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ctypes/__init__.py", line 378, in __getattr__
    func = self.__getitem__(name)
  File "/usr/local/Cellar/python/2.7.10/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ctypes/__init__.py", line 383, in __getitem__
    func = self._FuncPtr((name_or_ordinal, self))
AttributeError: dlsym(0x7f81ca493370, EC_KEY_set_public_key_affine_coordinates): symbol not found

What's the meaning of this error message, and how could it be fixed?

For reference, I am using the following configuration:

• OS: Mac OSX 10.10.5

• NFC Reader: RC-S380

• Python 2.7.10

• pip 8.1.2

• nfcpy (0.11.1)