diff --git a/resize.c b/resize.c
index 5b89b093..330c37b5 100644
--- a/resize.c
+++ b/resize.c
@@ -104,7 +104,7 @@ recalculate_sizes(void)
 			if (flag)
 				has = s->curw->window == w;
 			else
-				has = session_has(s, w) != NULL;
+				has = session_has(s, w);
 			if (has) {
 				if (s->sx < ssx)
 					ssx = s->sx;
diff --git a/server-fn.c b/server-fn.c
index 83ea9474..c5487aa6 100644
--- a/server-fn.c
+++ b/server-fn.c
@@ -199,7 +199,7 @@ server_status_window(struct window *w)
 	 */
 
 	RB_FOREACH(s, sessions, &sessions) {
-		if (session_has(s, w) != NULL)
+		if (session_has(s, w))
 			server_status_session(s);
 	}
 }
@@ -268,7 +268,7 @@ server_kill_window(struct window *w)
 		s = next_s;
 		next_s = RB_NEXT(sessions, &sessions, s);
 
-		if (session_has(s, w) == NULL)
+		if (!session_has(s, w))
 			continue;
 		server_unzoom_window(w);
 		while ((wl = winlink_find_by_window(&s->windows, w)) != NULL) {
diff --git a/session.c b/session.c
index 03ddb10d..c0535725 100644
--- a/session.c
+++ b/session.c
@@ -309,16 +309,16 @@ session_detach(struct session *s, struct winlink *wl)
 }
 
 /* Return if session has window. */
-struct winlink *
+int
 session_has(struct session *s, struct window *w)
 {
 	struct winlink	*wl;
 
 	RB_FOREACH(wl, winlinks, &s->windows) {
 		if (wl->window == w)
-			return (wl);
+			return (1);
 	}
-	return (NULL);
+	return (0);
 }
 
 struct winlink *
diff --git a/tmux.h b/tmux.h
index e52b14f1..a47218e5 100644
--- a/tmux.h
+++ b/tmux.h
@@ -2321,7 +2321,7 @@ struct winlink	*session_new(struct session *, const char *, int, char **,
 struct winlink	*session_attach(struct session *, struct window *, int,
 		     char **);
 int		 session_detach(struct session *, struct winlink *);
-struct winlink	*session_has(struct session *, struct window *);
+int		 session_has(struct session *, struct window *);
 int		 session_next(struct session *, int);
 int		 session_previous(struct session *, int);
 int		 session_select(struct session *, int);