diff --git a/src/proto/channel.pro b/src/proto/channel.pro
index 53c5dab..6a52d8b 100644
--- a/src/proto/channel.pro
+++ b/src/proto/channel.pro
@@ -14,15 +14,15 @@
 void channel_set_pipes(channel_T *channel, sock_T in, sock_T out, sock_T err);
 void channel_set_job(channel_T *channel, job_T *job, jobopt_T *options);
 void channel_set_options(channel_T *channel, jobopt_T *opt);
-void channel_set_req_callback(channel_T *channel, int part, char_u *callback, partial_T *partial, int id);
+void channel_set_req_callback(channel_T *channel, ch_part_T part, char_u *callback, partial_T *partial, int id);
 void channel_buffer_free(buf_T *buf);
 void channel_write_any_lines(void);
 void channel_write_new_lines(buf_T *buf);
-readq_T *channel_peek(channel_T *channel, int part);
+readq_T *channel_peek(channel_T *channel, ch_part_T part);
 char_u *channel_first_nl(readq_T *node);
-char_u *channel_get(channel_T *channel, int part);
-void channel_consume(channel_T *channel, int part, int len);
-int channel_collapse(channel_T *channel, int part, int want_nl);
+char_u *channel_get(channel_T *channel, ch_part_T part);
+void channel_consume(channel_T *channel, ch_part_T part, int len);
+int channel_collapse(channel_T *channel, ch_part_T part, int want_nl);
 int channel_can_write_to(channel_T *channel);
 int channel_is_open(channel_T *channel);
 char *channel_status(channel_T *channel, int req_part);
@@ -31,13 +31,12 @@
 void channel_close_in(channel_T *channel);
 void channel_clear(channel_T *channel);
 void channel_free_all(void);
-char_u *channel_read_block(channel_T *channel, int part, int timeout);
-int channel_read_json_block(channel_T *channel, int part, int timeout_arg, int id, typval_T **rettv);
+char_u *channel_read_block(channel_T *channel, ch_part_T part, int timeout);
+int channel_read_json_block(channel_T *channel, ch_part_T part, int timeout_arg, int id, typval_T **rettv);
 void common_channel_read(typval_T *argvars, typval_T *rettv, int raw);
-channel_T *channel_fd2channel(sock_T fd, int *partp);
+channel_T *channel_fd2channel(sock_T fd, ch_part_T *partp);
 void channel_handle_events(void);
-int channel_send(channel_T *channel, int part, char_u *buf, int len, char *fun);
-channel_T *send_common(typval_T *argvars, char_u *text, int id, int eval, jobopt_T *opt, char *fun, int *part_read);
+int channel_send(channel_T *channel, ch_part_T part, char_u *buf, int len, char *fun);
 void ch_expr_common(typval_T *argvars, typval_T *rettv, int eval);
 void ch_raw_common(typval_T *argvars, typval_T *rettv, int eval);
 int channel_poll_setup(int nfd_in, void *fds_in);
@@ -46,14 +45,14 @@
 int channel_select_check(int ret_in, void *rfds_in, void *wfds_in);
 int channel_parse_messages(void);
 int set_ref_in_channel(int copyID);
-int channel_part_send(channel_T *channel);
-int channel_part_read(channel_T *channel);
-ch_mode_T channel_get_mode(channel_T *channel, int part);
-int channel_get_timeout(channel_T *channel, int part);
+ch_part_T channel_part_send(channel_T *channel);
+ch_part_T channel_part_read(channel_T *channel);
+ch_mode_T channel_get_mode(channel_T *channel, ch_part_T part);
+int channel_get_timeout(channel_T *channel, ch_part_T part);
 void clear_job_options(jobopt_T *opt);
 void free_job_options(jobopt_T *opt);
 int get_job_options(typval_T *tv, jobopt_T *opt, int supported);
-channel_T *get_channel_arg(typval_T *tv, int check_open, int reading, int part);
+channel_T *get_channel_arg(typval_T *tv, int check_open, int reading, ch_part_T part);
 void job_free_all(void);
 int set_ref_in_job(int copyID);
 void job_unref(job_T *job);