1 files changed, 1 insertions, 0 deletions
diff --git a/src/nvim/ui.c b/src/nvim/ui.c
index 33c7d0c1fe..4c640693cc 100644
--- a/src/nvim/ui.c
+++ b/src/nvim/ui.c
@@ -506,6 +506,7 @@ handle_T ui_cursor_grid(void)
 
 void ui_flush(void)
 {
+  assert(!ui_client_channel_id);
   if (!ui_active()) {
     return;
   }