diff --git a/libweston/data-device.c b/libweston/data-device.c
index e19409fc..865d7497 100644
--- a/libweston/data-device.c
+++ b/libweston/data-device.c
@@ -1152,7 +1152,9 @@ weston_seat_set_selection(struct weston_seat *seat,
 
 	seat->selection_data_source = source;
 	seat->selection_serial = serial;
-	source->set_selection = true;
+
+	if (source)
+		source->set_selection = true;
 
 	if (keyboard)
 		focus = keyboard->focus;