Index: src_plugins/dialogs/dlg_flag_edit.c
===================================================================
--- src_plugins/dialogs/dlg_flag_edit.c	(revision 22972)
+++ src_plugins/dialogs/dlg_flag_edit.c	(revision 22973)
@@ -27,6 +27,7 @@
 #include "flag.h"
 #include "flag_str.h"
 #include "change.h"
+#include "undo.h"
 
 typedef struct{
 	unsigned long flag_bit[64];