diff --git a/src/signs_gui.cpp b/src/signs_gui.cpp
--- a/src/signs_gui.cpp
+++ b/src/signs_gui.cpp
@@ -26,6 +26,7 @@
 #include "hotkeys.h"
 #include "transparency.h"
 #include "gui.h"
+#include "signs_cmd.h"
 
 #include "widgets/sign_widget.h"
 
@@ -413,7 +414,7 @@ Window *ShowSignList()
 static bool RenameSign(SignID index, const char *text)
 {
 	bool remove = StrEmpty(text);
-	DoCommandP(CMD_RENAME_SIGN, StrEmpty(text) ? STR_ERROR_CAN_T_DELETE_SIGN : STR_ERROR_CAN_T_CHANGE_SIGN_NAME, 0, index, 0, text);
+	Command<CMD_RENAME_SIGN>::Post(StrEmpty(text) ? STR_ERROR_CAN_T_DELETE_SIGN : STR_ERROR_CAN_T_CHANGE_SIGN_NAME, 0, index, 0, text);
 	return remove;
 }