diff --git a/src/mbyte.c b/src/mbyte.c
index a626f50..76eab4e 100644
--- a/src/mbyte.c
+++ b/src/mbyte.c
@@ -5510,6 +5510,8 @@
     int		    i;
     listitem_T	    **ptrs;
     cw_interval_T   *table;
+    cw_interval_T   *cw_table_save;
+    size_t	    cw_table_size_save;
 
     if (in_vim9script() && check_for_list_arg(argvars, 0) == FAIL)
 	return;
@@ -5620,9 +5622,41 @@
     }
 
     vim_free(ptrs);
-    vim_free(cw_table);
+
+    cw_table_save = cw_table;
+    cw_table_size_save = cw_table_size;
     cw_table = table;
     cw_table_size = l->lv_len;
+
+    // Check that the new value does not conflict with 'fillchars' or
+    // 'listchars'.
+    if (set_chars_option(curwin, &p_fcs) != NULL)
+    {
+	emsg(_(e_conflicts_with_value_of_fillchars));
+	cw_table = cw_table_save;
+	cw_table_size = cw_table_size_save;
+	vim_free(table);
+	return;
+    }
+    else
+    {
+	tabpage_T	*tp;
+	win_T	*wp;
+
+	FOR_ALL_TAB_WINDOWS(tp, wp)
+	{
+	    if (set_chars_option(wp, &wp->w_p_lcs) != NULL)
+	    {
+		emsg((e_conflicts_with_value_of_listchars));
+		cw_table = cw_table_save;
+		cw_table_size = cw_table_size_save;
+		vim_free(table);
+		return;
+	    }
+	}
+    }
+
+    vim_free(cw_table_save);
 }
 
     void