diff --git a/src/main/java/eu/siacs/conversations/parser/MessageParser.java b/src/main/java/eu/siacs/conversations/parser/MessageParser.java
index 10c9e9764..72aaf1fa0 100644
--- a/src/main/java/eu/siacs/conversations/parser/MessageParser.java
+++ b/src/main/java/eu/siacs/conversations/parser/MessageParser.java
@@ -869,7 +869,10 @@ public class MessageParser extends AbstractParser implements OnMessagePacketRece
         public boolean execute(Account account) {
             if (jid != null) {
                 Conversation conversation = mXmppConnectionService.findOrCreateConversation(account, jid, true, false);
-                if (!conversation.getMucOptions().online()) {
+                if (conversation.getMucOptions().online()) {
+                    Log.d(Config.LOGTAG,account.getJid().asBareJid()+": received invite to "+jid+" but muc is considered to be online");
+                    mXmppConnectionService.mucSelfPingAndRejoin(conversation);
+                } else {
                     conversation.getMucOptions().setPassword(password);
                     mXmppConnectionService.databaseBackend.updateConversation(conversation);
                     mXmppConnectionService.joinMuc(conversation, inviter != null && inviter.mutualPresenceSubscription());
diff --git a/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java b/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
index 5eeaab99c..a596f3b87 100644
--- a/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
+++ b/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
@@ -1974,7 +1974,7 @@ public class XmppConnectionService extends Service {
 	    archiveConversation(conversation, true);
     }
 
-	private void archiveConversation(Conversation conversation, final boolean maySyncronizeWithBookmarks) {
+	private void archiveConversation(Conversation conversation, final boolean maySynchronizeWithBookmarks) {
 		getNotificationService().clear(conversation);
 		conversation.setStatus(Conversation.STATUS_ARCHIVED);
 		conversation.setNextMessage(null);
@@ -1983,7 +1983,7 @@ public class XmppConnectionService extends Service {
 			if (conversation.getMode() == Conversation.MODE_MULTI) {
 				if (conversation.getAccount().getStatus() == Account.State.ONLINE) {
 					Bookmark bookmark = conversation.getBookmark();
-					if (maySyncronizeWithBookmarks && bookmark != null && synchronizeWithBookmarks()) {
+					if (maySynchronizeWithBookmarks && bookmark != null && synchronizeWithBookmarks()) {
 						if (conversation.getMucOptions().getError() == MucOptions.Error.DESTROYED) {
 							Account account = bookmark.getAccount();
 							bookmark.setConversation(null);
@@ -2431,6 +2431,26 @@ public class XmppConnectionService extends Service {
 		}
 	}
 
+	public void mucSelfPingAndRejoin(final Conversation conversation) {
+	    final Jid self = conversation.getMucOptions().getSelf().getFullJid();
+	    final IqPacket ping = new IqPacket(IqPacket.TYPE.GET);
+	    ping.setTo(self);
+	    ping.addChild("ping", Namespace.PING);
+	    sendIqPacket(conversation.getAccount(), ping, (account, response) -> {
+	        if (response.getType() == IqPacket.TYPE.ERROR) {
+	            Element error = response.findChild("error");
+	            if (error == null || error.hasChild("service-unavailable") || error.hasChild("feature-not-implemented") || error.hasChild("item-not-found")) {
+	                Log.d(Config.LOGTAG,account.getJid().asBareJid()+": ping to "+self+" came back as ignorable error");
+                } else {
+	                Log.d(Config.LOGTAG,account.getJid().asBareJid()+": ping to "+self+" failed. attempting rejoin");
+	                joinMuc(conversation);
+                }
+            } else if (response.getType() == IqPacket.TYPE.RESULT) {
+	            Log.d(Config.LOGTAG,account.getJid().asBareJid()+": ping to "+self+" came back fine");
+            }
+        });
+    }
+
 	public void joinMuc(Conversation conversation) {
 		joinMuc(conversation, null, false);
 	}
diff --git a/src/main/java/eu/siacs/conversations/xml/Namespace.java b/src/main/java/eu/siacs/conversations/xml/Namespace.java
index 0d478c586..73d3d452d 100644
--- a/src/main/java/eu/siacs/conversations/xml/Namespace.java
+++ b/src/main/java/eu/siacs/conversations/xml/Namespace.java
@@ -27,4 +27,5 @@ public final class Namespace {
 	public static final String AVATAR_CONVERSION = "urn:xmpp:pep-vcard-conversion:0";
 	public static final String JINGLE_TRANSPORTS_S5B = "urn:xmpp:jingle:transports:s5b:1";
 	public static final String JINGLE_TRANSPORTS_IBB = "urn:xmpp:jingle:transports:ibb:1";
+	public static final String PING = "urn:xmpp:ping";
 }
diff --git a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
index 90a7fe02c..d157926b6 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java
@@ -1417,7 +1417,7 @@ public class XmppConnection implements Runnable {
         if (!r()) {
             final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
             iq.setFrom(account.getJid());
-            iq.addChild("ping", "urn:xmpp:ping");
+            iq.addChild("ping", Namespace.PING);
             this.sendIqPacket(iq, null);
         }
         this.lastPingSent = SystemClock.elapsedRealtime();