diff --git a/src/mbyte.c b/src/mbyte.c
index 6046d7d..edca9a7 100644
--- a/src/mbyte.c
+++ b/src/mbyte.c
@@ -4541,7 +4541,7 @@
 {
     if (State & CMDLINE)
 	preedit_start_col = cmdline_getvcol_cursor();
-    else if (curwin != NULL)
+    else if (curwin != NULL && curwin->w_buffer != NULL)
 	getvcol(curwin, &curwin->w_cursor, &preedit_start_col, NULL, NULL);
     /* Prevent that preediting marks the buffer as changed. */
     xim_changed_while_preediting = curbuf->b_changed;