diff --git a/Modules/_multiprocessing/connection.h b/Modules/_multiprocessing/connection.h
index 155b61b..458d1d3 100644
--- a/Modules/_multiprocessing/connection.h
+++ b/Modules/_multiprocessing/connection.h
@@ -354,7 +354,7 @@
 	}
 
 	Py_BEGIN_ALLOW_THREADS
-	res = conn_poll(self, timeout);
+	res = conn_poll(self, timeout, _save);
 	Py_END_ALLOW_THREADS
 
 	switch (res) {
diff --git a/Modules/_multiprocessing/socket_connection.c b/Modules/_multiprocessing/socket_connection.c
index e5d2d15..ad4005b 100644
--- a/Modules/_multiprocessing/socket_connection.c
+++ b/Modules/_multiprocessing/socket_connection.c
@@ -153,11 +153,23 @@
  */
 
 static int
-conn_poll(ConnectionObject *conn, double timeout)
+conn_poll(ConnectionObject *conn, double timeout, PyThreadState *_save)
 {
 	int res;
 	fd_set rfds;
 
+	/*
+	 * Verify the handle, issue 3321. Not required for windows.
+	 */ 
+	#ifndef MS_WINDOWS
+		if (((int)conn->handle) < 0 || ((int)conn->handle) >= FD_SETSIZE) {
+			Py_BLOCK_THREADS
+			PyErr_SetString(PyExc_IOError, "handle out of range in select()");
+			Py_UNBLOCK_THREADS
+			return MP_EXCEPTION_HAS_BEEN_SET;
+		}
+	#endif
+
 	FD_ZERO(&rfds);
 	FD_SET((SOCKET)conn->handle, &rfds);