diff --git a/Lib/asyncio/base_subprocess.py b/Lib/asyncio/base_subprocess.py
index fb8c2ba..28482b7 100644
--- a/Lib/asyncio/base_subprocess.py
+++ b/Lib/asyncio/base_subprocess.py
@@ -87,6 +87,12 @@
     def _start(self, args, shell, stdin, stdout, stderr, bufsize, **kwargs):
         raise NotImplementedError
 
+    def set_protocol(self, protocol):
+        self._protocol = protocol
+
+    def get_protocol(self):
+        return self._protocol
+
     def is_closing(self):
         return self._closed
 
diff --git a/Lib/asyncio/proactor_events.py b/Lib/asyncio/proactor_events.py
index 4b6067a..68a523a 100644
--- a/Lib/asyncio/proactor_events.py
+++ b/Lib/asyncio/proactor_events.py
@@ -66,6 +66,12 @@
     def _set_extra(self, sock):
         self._extra['pipe'] = sock
 
+    def set_protocol(self, protocol):
+        self._protocol = protocol
+
+    def get_protocol(self):
+        return self._protocol
+
     def is_closing(self):
         return self._closing
 
diff --git a/Lib/asyncio/selector_events.py b/Lib/asyncio/selector_events.py
index 34cce6b..1850bdb 100644
--- a/Lib/asyncio/selector_events.py
+++ b/Lib/asyncio/selector_events.py
@@ -560,6 +560,12 @@
     def abort(self):
         self._force_close(None)
 
+    def set_protocol(self, protocol):
+        self._protocol = protocol
+
+    def get_protocol(self):
+        return self._protocol
+
     def is_closing(self):
         return self._closing
 
diff --git a/Lib/asyncio/sslproto.py b/Lib/asyncio/sslproto.py
index f0f642e..92d3c4c 100644
--- a/Lib/asyncio/sslproto.py
+++ b/Lib/asyncio/sslproto.py
@@ -305,6 +305,12 @@
         """Get optional transport information."""
         return self._ssl_protocol._get_extra_info(name, default)
 
+    def set_protocol(self, protocol):
+        self._app_protocol = protocol
+
+    def get_protocol(self):
+        return self._app_protocol
+
     def is_closing(self):
         return self._closed
 
diff --git a/Lib/asyncio/transports.py b/Lib/asyncio/transports.py
index 9a6d919..0db0875 100644
--- a/Lib/asyncio/transports.py
+++ b/Lib/asyncio/transports.py
@@ -33,6 +33,14 @@
         """
         raise NotImplementedError
 
+    def set_protocol(self, protocol):
+        """Set a new protocol."""
+        raise NotImplementedError
+
+    def get_protocol(self):
+        """Return the current protocol."""
+        raise NotImplementedError
+
 
 class ReadTransport(BaseTransport):
     """Interface for read-only transports."""
diff --git a/Lib/asyncio/unix_events.py b/Lib/asyncio/unix_events.py
index d183f60..4222054 100644
--- a/Lib/asyncio/unix_events.py
+++ b/Lib/asyncio/unix_events.py
@@ -374,6 +374,12 @@
     def resume_reading(self):
         self._loop.add_reader(self._fileno, self._read_ready)
 
+    def set_protocol(self, protocol):
+        self._protocol = protocol
+
+    def get_protocol(self):
+        return self._protocol
+
     def is_closing(self):
         return self._closing
 
@@ -571,6 +577,12 @@
             self._loop.remove_reader(self._fileno)
             self._loop.call_soon(self._call_connection_lost, None)
 
+    def set_protocol(self, protocol):
+        self._protocol = protocol
+
+    def get_protocol(self):
+        return self._protocol
+
     def is_closing(self):
         return self._closing
 
diff --git a/Lib/test/test_asyncio/test_sslproto.py b/Lib/test/test_asyncio/test_sslproto.py
index 8d52335..7dfa6c2 100644
--- a/Lib/test/test_asyncio/test_sslproto.py
+++ b/Lib/test/test_asyncio/test_sslproto.py
@@ -25,6 +25,7 @@
         sslcontext = test_utils.dummy_ssl_context()
         app_proto = asyncio.Protocol()
         proto = sslproto.SSLProtocol(self.loop, app_proto, sslcontext, waiter)
+        self.assertIs(proto._app_transport.get_protocol(), app_proto)
         self.addCleanup(proto._app_transport.close)
         return proto