diff --git a/src/ex_cmds2.c b/src/ex_cmds2.c
index 26b588c..8a11fbb 100644
--- a/src/ex_cmds2.c
+++ b/src/ex_cmds2.c
@@ -3749,6 +3749,7 @@
 ex_options(
     exarg_T	*eap UNUSED)
 {
+    vim_setenv((char_u *)"OPTWIN_CMD", (char_u *)(cmdmod.tab ? "tab" : ""));
     cmd_source((char_u *)SYS_OPTWIN_FILE, NULL);
 }
 #endif