diff --git a/AdcProtocol.go b/AdcProtocol.go
index 56b42aa..e079df9 100644
--- a/AdcProtocol.go
+++ b/AdcProtocol.go
@@ -229,14 +229,36 @@ func (this *AdcProtocol) ProcessCommand(msg string) {
 	case "IQUI":
 		// Error message from the hub
 		// IQUI V3M6 DI1 MSNick\staken,\splease\spick\sanother\sone TL-1
-		flags, err := this.parts2flags(parts[1:])
+		if len(parts) < 2 {
+			this.malformed(parts)
+			return
+		}
+
+		sid := parts[1]
+
+		flags, err := this.parts2flags(parts[2:])
 		if err != nil {
 			return
 		}
-		if msg, ok := flags["MS"]; ok {
-			this.hc.processEvent(HubEvent{EventType: EVENT_SYSTEM_MESSAGE_FROM_HUB, Message: "The hub is closing our connection because: " + this.unescape(msg)})
+
+		if sid == this.sid {
+			if msg, ok := flags["MS"]; ok {
+				this.hc.processEvent(HubEvent{EventType: EVENT_SYSTEM_MESSAGE_FROM_HUB, Message: "The hub is closing our connection because: " + this.unescape(msg)})
+			} else {
+				this.hc.processEvent(HubEvent{EventType: EVENT_SYSTEM_MESSAGE_FROM_HUB, Message: "The hub is closing our connection"})
+			}
 		} else {
-			this.hc.processEvent(HubEvent{EventType: EVENT_SYSTEM_MESSAGE_FROM_HUB, Message: "The hub is closing our connection"})
+			this.hc.usersMut.Lock()
+			defer this.hc.usersMut.Unlock()
+			otherSidNick, ok := this.hc.userSIDs[sid]
+			if ok {
+				delete(this.hc.userSIDs, sid)
+				delete(this.hc.users, otherSidNick)
+				this.hc.processEvent(HubEvent{EventType: EVENT_USER_PART, Nick: otherSidNick})
+			} else {
+				// ??
+				this.logError(fmt.Errorf("An unknown user quit the hub (SID=%s)", sid))
+			}
 		}
 
 	case "BMSG":