diff --git a/oauth2client/crypt.py b/oauth2client/crypt.py
index <HASH>..<HASH> 100644
--- a/oauth2client/crypt.py
+++ b/oauth2client/crypt.py
@@ -128,7 +128,7 @@ try:
       if parsed_pem_key:
         pkey = crypto.load_privatekey(crypto.FILETYPE_PEM, parsed_pem_key)
       else:
-        pkey = crypto.load_pkcs12(key, password).get_privatekey()
+        pkey = crypto.load_pkcs12(key, password.encode('utf8')).get_privatekey()
       return OpenSSLSigner(pkey)
 
 except ImportError:
Handle PKCS<I> unicode passwords

The load_pkcs<I> can't handle passing unicode objects. Instead, encode the given 

string as bytes before passing to the function.