diff --git a/modules/core/m_nick.c b/modules/core/m_nick.c
index 0caa4596..51c04980 100644
--- a/modules/core/m_nick.c
+++ b/modules/core/m_nick.c
@@ -94,7 +94,7 @@ static int change_remote_nick(struct Client *, struct Client *, time_t,
 static int clean_nick(const char *, int loc_client);
 static int clean_username(const char *);
 static int clean_host(const char *);
-static int clean_uid(const char *uid);
+static int clean_uid(const char *uid, const char *sid);
 
 static void set_initial_nick(struct Client *client_p, struct Client *source_p, char *nick);
 static void change_local_nick(struct Client *client_p, struct Client *source_p, char *nick, int);
@@ -362,7 +362,7 @@ ms_uid(struct Client *client_p, struct Client *source_p, int parc, const char *p
 		return 0;
 	}
 
-	if(!clean_uid(parv[8]))
+	if(!clean_uid(parv[8], source_p->id))
 	{
 		rb_snprintf(squitreason, sizeof squitreason,
 				"Invalid UID %s for nick %s on %s",
@@ -453,7 +453,7 @@ ms_euid(struct Client *client_p, struct Client *source_p, int parc, const char *
 		return 0;
 	}
 
-	if(!clean_uid(parv[8]))
+	if(!clean_uid(parv[8], source_p->id))
 	{
 		rb_snprintf(squitreason, sizeof squitreason,
 				"Invalid UID %s for nick %s on %s",
@@ -623,10 +623,13 @@ clean_host(const char *host)
 }
 
 static int
-clean_uid(const char *uid)
+clean_uid(const char *uid, const char *sid)
 {
 	int len = 1;
 
+	if(strncmp(uid, sid, strlen(sid)))
+		return 0;
+
 	if(!IsDigit(*uid++))
 		return 0;