--- a/src/python/grpcio/grpc/_cython/_cygrpc/aio/completion_queue.pyx.pxi       (index)
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/aio/completion_queue.pyx.pxi       (working tree)
@@ -22,7 +22,7 @@ IF UNAME_SYSNAME == "Windows":
     cdef void _unified_socket_write(int fd) nogil:
         win_socket_send(<WIN_SOCKET>fd, b"1", 1, 0)
 ELSE:
-    from posix cimport unistd
+    cimport posix.unistd as unistd

     cdef void _unified_socket_write(int fd) nogil:
         unistd.write(fd, b"1", 1)