diff --git a/cmd-attach-session.c b/cmd-attach-session.c
index 79e14616..46d568b4 100644
--- a/cmd-attach-session.c
+++ b/cmd-attach-session.c
@@ -69,9 +69,12 @@ cmd_attach_session(struct cmd_q *cmdq, const char *tflag, int dflag, int rflag,
 	} else {
 		if ((s = cmd_find_session(cmdq, tflag, 1)) == NULL)
 			return (CMD_RETURN_ERROR);
-		w = cmd_lookup_windowid(tflag);
-		if (w == NULL && (wp = cmd_lookup_paneid(tflag)) != NULL)
-			w = wp->window;
+		w = window_find_by_id_str(tflag);
+		if (w == NULL) {
+			wp = window_pane_find_by_id_str(tflag);
+			if (wp != NULL)
+				w = wp->window;
+		}
 		if (w != NULL)
 			wl = winlink_find_by_window(&s->windows, w);
 	}
diff --git a/cmd-switch-client.c b/cmd-switch-client.c
index 8c4daf97..18de0eb1 100644
--- a/cmd-switch-client.c
+++ b/cmd-switch-client.c
@@ -99,10 +99,12 @@ cmd_switch_client_exec(struct cmd *self, struct cmd_q *cmdq)
 		} else {
 			if ((s = cmd_find_session(cmdq, tflag, 1)) == NULL)
 				return (CMD_RETURN_ERROR);
-			w = cmd_lookup_windowid(tflag);
-			if (w == NULL &&
-			    (wp = cmd_lookup_paneid(tflag)) != NULL)
-				w = wp->window;
+			w = window_find_by_id_str(tflag);
+			if (w == NULL) {
+				wp = window_pane_find_by_id_str(tflag);
+				if (wp != NULL)
+					w = wp->window;
+			}
 			if (w != NULL)
 				wl = winlink_find_by_window(&s->windows, w);
 		}
diff --git a/cmd.c b/cmd.c
index b81ffb36..4be5a4d6 100644
--- a/cmd.c
+++ b/cmd.c
@@ -124,7 +124,6 @@ struct session	*cmd_choose_session(int);
 struct client	*cmd_choose_client(struct client_list *);
 struct client	*cmd_lookup_client(const char *);
 struct session	*cmd_lookup_session(struct cmd_q *, const char *, int *);
-struct session	*cmd_lookup_session_id(const char *);
 struct winlink	*cmd_lookup_window(struct session *, const char *, int *);
 int		 cmd_lookup_index(struct session *, const char *, int *);
 struct winlink	*cmd_lookup_winlink_windowid(struct session *, const char *);
@@ -639,21 +638,6 @@ cmd_lookup_client(const char *name)
 	return (NULL);
 }
 
-/* Find the target session or report an error and return NULL. */
-struct session *
-cmd_lookup_session_id(const char *arg)
-{
-	char	*endptr;
-	long	 id;
-
-	if (arg[0] != '$')
-		return (NULL);
-	id = strtol(arg + 1, &endptr, 10);
-	if (arg[1] != '\0' && *endptr == '\0')
-		return (session_find_by_id(id));
-	return (NULL);
-}
-
 /* Lookup a session by name. If no session is found, NULL is returned. */
 struct session *
 cmd_lookup_session(struct cmd_q *cmdq, const char *name, int *ambiguous)
@@ -665,13 +649,13 @@ cmd_lookup_session(struct cmd_q *cmdq, const char *name, int *ambiguous)
 	*ambiguous = 0;
 
 	/* Look for $id first. */
-	if ((s = cmd_lookup_session_id(name)) != NULL)
+	if ((s = session_find_by_id_str(name)) != NULL)
 		return (s);
 
 	/* Try as pane or window id. */
-	if ((wp = cmd_lookup_paneid(name)) != NULL)
+	if ((wp = window_pane_find_by_id_str(name)) != NULL)
 		return (cmd_window_session(cmdq, wp->window, NULL));
-	if ((w = cmd_lookup_windowid(name)) != NULL)
+	if ((w = window_find_by_id_str(name)) != NULL)
 		return (cmd_window_session(cmdq, w, NULL));
 
 	/*
@@ -722,12 +706,12 @@ cmd_lookup_window(struct session *s, const char *name, int *ambiguous)
 	    return (wl);
 
 	/* Lookup as pane or window id. */
-	if ((wp = cmd_lookup_paneid(name)) != NULL) {
+	if ((wp = window_pane_find_by_id_str(name)) != NULL) {
 		wl = winlink_find_by_window(&s->windows, wp->window);
 		if (wl != NULL)
 			return (wl);
 	}
-	if ((w = cmd_lookup_windowid(name)) != NULL) {
+	if ((w = window_find_by_id_str(name)) != NULL) {
 		wl = winlink_find_by_window(&s->windows, w);
 		if (wl != NULL)
 			return (wl);
@@ -795,22 +779,6 @@ cmd_lookup_index(struct session *s, const char *name, int *ambiguous)
 	return (-1);
 }
 
-/* Lookup pane id. An initial % means a pane id. */
-struct window_pane *
-cmd_lookup_paneid(const char *arg)
-{
-	const char	*errstr;
-	u_int		 paneid;
-
-	if (*arg != '%')
-		return (NULL);
-
-	paneid = strtonum(arg + 1, 0, UINT_MAX, &errstr);
-	if (errstr != NULL)
-		return (NULL);
-	return (window_pane_find_by_id(paneid));
-}
-
 /* Lookup window id in a session. An initial @ means a window id. */
 struct winlink *
 cmd_lookup_winlink_windowid(struct session *s, const char *arg)
@@ -827,22 +795,6 @@ cmd_lookup_winlink_windowid(struct session *s, const char *arg)
 	return (winlink_find_by_window_id(&s->windows, windowid));
 }
 
-/* Lookup window id. An initial @ means a window id. */
-struct window *
-cmd_lookup_windowid(const char *arg)
-{
-	const char	*errstr;
-	u_int		 windowid;
-
-	if (*arg != '@')
-		return (NULL);
-
-	windowid = strtonum(arg + 1, 0, UINT_MAX, &errstr);
-	if (errstr != NULL)
-		return (NULL);
-	return (window_find_by_id(windowid));
-}
-
 /* Find session and winlink for window. */
 struct session *
 cmd_window_session(struct cmd_q *cmdq, struct window *w, struct winlink **wlp)
@@ -1252,7 +1204,7 @@ cmd_find_pane(struct cmd_q *cmdq,
 	}
 
 	/* Lookup as pane id. */
-	if ((*wpp = cmd_lookup_paneid(arg)) != NULL) {
+	if ((*wpp = window_pane_find_by_id_str(arg)) != NULL) {
 		s = cmd_window_session(cmdq, (*wpp)->window, &wl);
 		if (sp != NULL)
 			*sp = s;
diff --git a/session.c b/session.c
index c0535725..224f1f32 100644
--- a/session.c
+++ b/session.c
@@ -70,6 +70,22 @@ session_find(const char *name)
 	return (RB_FIND(sessions, &sessions, &s));
 }
 
+/* Find session by id parsed from a string. */
+struct session *
+session_find_by_id_str(const char *s)
+{
+	const char	*errstr;
+	u_int		 id;
+
+	if (*s != '$')
+		return (NULL);
+
+	id = strtonum(s + 1, 0, UINT_MAX, &errstr);
+	if (errstr != NULL)
+		return (NULL);
+	return (session_find_by_id(id));
+}
+
 /* Find session by id. */
 struct session *
 session_find_by_id(u_int id)
diff --git a/tmux.h b/tmux.h
index c38149ab..3f8829ce 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1766,8 +1766,6 @@ int		 cmd_find_index(struct cmd_q *, const char *,
 struct winlink	*cmd_find_pane(struct cmd_q *, const char *, struct session **,
 		     struct window_pane **);
 char		*cmd_template_replace(const char *, const char *, int);
-struct window	*cmd_lookup_windowid(const char *);
-struct window_pane *cmd_lookup_paneid(const char *);
 extern const struct cmd_entry *cmd_table[];
 extern const struct cmd_entry cmd_attach_session_entry;
 extern const struct cmd_entry cmd_bind_key_entry;
@@ -2147,6 +2145,7 @@ struct winlink	*winlink_previous_by_number(struct winlink *, struct session *,
 		     int);
 void		 winlink_stack_push(struct winlink_stack *, struct winlink *);
 void		 winlink_stack_remove(struct winlink_stack *, struct winlink *);
+struct window	*window_find_by_id_str(const char *);
 struct window	*window_find_by_id(u_int);
 struct window	*window_create1(u_int, u_int);
 struct window	*window_create(const char *, int, char **, const char *,
@@ -2172,6 +2171,7 @@ struct window_pane *window_pane_previous_by_number(struct window *,
 int		 window_pane_index(struct window_pane *, u_int *);
 u_int		 window_count_panes(struct window *);
 void		 window_destroy_panes(struct window *);
+struct window_pane *window_pane_find_by_id_str(const char *);
 struct window_pane *window_pane_find_by_id(u_int);
 struct window_pane *window_pane_create(struct window *, u_int, u_int, u_int);
 void		 window_pane_destroy(struct window_pane *);
@@ -2309,6 +2309,7 @@ int	session_cmp(struct session *, struct session *);
 RB_PROTOTYPE(sessions, session, entry, session_cmp);
 int		 session_alive(struct session *);
 struct session	*session_find(const char *);
+struct session	*session_find_by_id_str(const char *);
 struct session	*session_find_by_id(u_int);
 struct session	*session_create(const char *, int, char **, const char *,
 		     int, struct environ *, struct termios *, int, u_int,
diff --git a/window.c b/window.c
index 5ca8aa0c..acbcd33d 100644
--- a/window.c
+++ b/window.c
@@ -253,6 +253,21 @@ winlink_stack_remove(struct winlink_stack *stack, struct winlink *wl)
 	}
 }
 
+struct window *
+window_find_by_id_str(const char* s)
+{
+	const char	*errstr;
+	u_int		 id;
+
+	if (*s != '@')
+		return (NULL);
+
+	id = strtonum(s + 1, 0, UINT_MAX, &errstr);
+	if (errstr != NULL)
+		return (NULL);
+	return (window_find_by_id(id));
+}
+
 struct window *
 window_find_by_id(u_int id)
 {
@@ -653,7 +668,21 @@ window_printable_flags(struct session *s, struct winlink *wl)
 	return (xstrdup(flags));
 }
 
-/* Find pane in global tree by id. */
+struct window_pane *
+window_pane_find_by_id_str(const char *s)
+{
+	const char	*errstr;
+	u_int		 id;
+
+	if (*s != '%')
+		return (NULL);
+
+	id = strtonum(s + 1, 0, UINT_MAX, &errstr);
+	if (errstr != NULL)
+		return (NULL);
+	return (window_pane_find_by_id(id));
+}
+
 struct window_pane *
 window_pane_find_by_id(u_int id)
 {