diff --git a/include/supported.h b/include/supported.h
index d92c9b1..beeb89c 100644
--- a/include/supported.h
+++ b/include/supported.h
@@ -36,6 +36,7 @@
 #define INCLUDED_supported_h
 
 extern void add_isupport(const char *, const char *(*)(const void *), const void *);
+extern void change_isupport(const char *, const char *(*)(const void *), const void *);
 extern void delete_isupport(const char *);
 extern void show_isupport(struct Client *);
 extern void init_isupport(void);
diff --git a/src/supported.c b/src/supported.c
index e0f617e..2f52479 100644
--- a/src/supported.c
+++ b/src/supported.c
@@ -111,6 +111,27 @@ add_isupport(const char *name, const char *(*func)(const void *), const void *pa
 	rb_dlinkAddTail(item, &item->node, &isupportlist);
 }
 
+void
+change_isupport(const char *name, const char *(*func)(const void *), const void *param)
+{
+	rb_dlink_node *ptr;
+	struct isupportitem *item;
+
+	RB_DLINK_FOREACH(ptr, isupportlist.head)
+	{
+		item = ptr->data;
+
+		if (!strcmp(item->name, name))
+		{
+			item->name = name;
+			item->func = func;
+			item->param = param;
+
+			break;
+		}
+	}
+}
+
 void
 delete_isupport(const char *name)
 {