diff --git a/OpenSSL/SSL.py b/OpenSSL/SSL.py
index f7e4a3b..ae8c3b1 100644
--- a/OpenSSL/SSL.py
+++ b/OpenSSL/SSL.py
@@ -193,10 +193,11 @@
         self._passphrase_userdata = None
         self._app_data = None
 
-    # SSL_CTX_set_app_data(self->ctx, self);
-    # SSL_CTX_set_mode(self->ctx, SSL_MODE_ENABLE_PARTIAL_WRITE |
-    #                             SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER |
-    #                             SSL_MODE_AUTO_RETRY);
+        # SSL_CTX_set_app_data(self->ctx, self);
+        # SSL_CTX_set_mode(self->ctx, SSL_MODE_ENABLE_PARTIAL_WRITE |
+        #                             SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER |
+        #                             SSL_MODE_AUTO_RETRY);
+        self.set_mode(_api.SSL_MODE_ENABLE_PARTIAL_WRITE)
 
 
     def load_verify_locations(self, cafile, capath=None):
@@ -830,6 +831,8 @@
                       API, the value is ignored
         :return: The number of bytes written
         """
+        if isinstance(buf, memoryview):
+            buf = buf.tobytes()
         if not isinstance(buf, bytes):
             raise TypeError("data must be a byte string")
         if not isinstance(flags, int):
@@ -852,6 +855,8 @@
                       API, the value is ignored
         :return: The number of bytes written
         """
+        if isinstance(buf, memoryview):
+            buf = buf.tobytes()
         if not isinstance(buf, bytes):
             raise TypeError("buf must be a byte string")
         if not isinstance(flags, int):