diff --git a/src/kmscon_seat.c b/src/kmscon_seat.c
index 91a8a5d..429e32c 100644
--- a/src/kmscon_seat.c
+++ b/src/kmscon_seat.c
@@ -474,6 +474,11 @@ void kmscon_session_unregister(struct kmscon_session *sess)
 	session_call(sess, KMSCON_SESSION_UNREGISTER, NULL);
 }
 
+bool kmscon_session_is_registered(struct kmscon_session *sess)
+{
+	return sess && sess->seat;
+}
+
 void kmscon_session_activate(struct kmscon_session *sess)
 {
 	if (!sess || !sess->seat)
diff --git a/src/kmscon_seat.h b/src/kmscon_seat.h
index 76f8e76..a9513c8 100644
--- a/src/kmscon_seat.h
+++ b/src/kmscon_seat.h
@@ -32,8 +32,8 @@
 #ifndef KMSCON_SEAT_H
 #define KMSCON_SEAT_H
 
+#include <stdbool.h>
 #include <stdlib.h>
-#include <unistd.h>
 #include "eloop.h"
 #include "uterm.h"
 
@@ -89,6 +89,7 @@ int kmscon_seat_register_session(struct kmscon_seat *seat,
 void kmscon_session_ref(struct kmscon_session *sess);
 void kmscon_session_unref(struct kmscon_session *sess);
 void kmscon_session_unregister(struct kmscon_session *sess);
+bool kmscon_session_is_registered(struct kmscon_session *sess);
 
 void kmscon_session_activate(struct kmscon_session *sess);
 void kmscon_session_deactivate(struct kmscon_session *sess);