diff --git a/app/src/main/java/com/nextcloud/talk/controllers/ChatController.kt b/app/src/main/java/com/nextcloud/talk/controllers/ChatController.kt
index edd46c7c7..c759f64f9 100644
--- a/app/src/main/java/com/nextcloud/talk/controllers/ChatController.kt
+++ b/app/src/main/java/com/nextcloud/talk/controllers/ChatController.kt
@@ -454,8 +454,17 @@ class ChatController(args: Bundle) :
                 R.layout.item_date_header, this
             )
 
+            var senderId = ""
+            if (!conversationUser?.userId.equals("?")) {
+                senderId = "users/" + conversationUser?.userId
+            } else {
+                senderId = currentConversation?.getActorType() + "/" + currentConversation?.getActorId()
+            }
+
+            Log.d(TAG, "Initialize TalkMessagesListAdapter with senderId: " + senderId)
+
             adapter = TalkMessagesListAdapter(
-                conversationUser?.userId,
+                senderId,
                 messageHolders,
                 ImageLoader { imageView, url, payload ->
                     val draweeController = Fresco.newDraweeControllerBuilder()
@@ -1050,18 +1059,6 @@ class ChatController(args: Bundle) :
             })
     }
 
-    private fun setSenderId() {
-        try {
-            val senderId = adapter?.javaClass?.getDeclaredField("senderId")
-            senderId?.isAccessible = true
-            senderId?.set(adapter, conversationUser?.userId)
-        } catch (e: NoSuchFieldException) {
-            Log.w(TAG, "Failed to set sender id")
-        } catch (e: IllegalAccessException) {
-            Log.w(TAG, "Failed to access and set field")
-        }
-    }
-
     private fun submitMessage() {
         if (messageInput != null) {
             val editable = messageInput!!.editableText
@@ -1351,14 +1348,6 @@ class ChatController(args: Bundle) :
                     chatMessage.activeUser = conversationUser
                     chatMessage.isLinkPreviewAllowed = isLinkPreviewAllowed
 
-                    // if credentials are empty, we're acting as a guest
-                    if (TextUtils.isEmpty(credentials) && myFirstMessage != null && !TextUtils.isEmpty(myFirstMessage?.toString())) {
-                        if (chatMessage.actorType == "guests") {
-                            conversationUser?.userId = chatMessage.actorId
-                            setSenderId()
-                        }
-                    }
-
                     val shouldScroll =
                         !isThereANewNotice && !shouldAddNewMessagesNotice && layoutManager?.findFirstVisibleItemPosition() == 0 || adapter != null && adapter?.itemCount == 0
 
diff --git a/app/src/main/java/com/nextcloud/talk/controllers/bottomsheet/OperationsMenuController.java b/app/src/main/java/com/nextcloud/talk/controllers/bottomsheet/OperationsMenuController.java
index d2a978a32..eae132ecd 100644
--- a/app/src/main/java/com/nextcloud/talk/controllers/bottomsheet/OperationsMenuController.java
+++ b/app/src/main/java/com/nextcloud/talk/controllers/bottomsheet/OperationsMenuController.java
@@ -347,6 +347,35 @@ public class OperationsMenuController extends BaseController {
                                     getRouter().pushController(RouterTransaction.with(new EntryMenuController(bundle))
                                                                        .pushChangeHandler(new HorizontalChangeHandler())
                                                                        .popChangeHandler(new HorizontalChangeHandler()));
+                                } else if (conversation.isGuest()) {
+                                    ncApi.joinRoom(credentials, ApiUtils.getUrlForParticipantsActive(apiVersion,
+                                                                                                     baseUrl,
+                                                                                                     conversationToken), null)
+                                            .subscribeOn(Schedulers.io())
+                                            .observeOn(AndroidSchedulers.mainThread())
+                                            .subscribe(new Observer<RoomOverall>() {
+                                                @Override
+                                                public void onSubscribe(Disposable d) {
+
+                                                }
+
+                                                @Override
+                                                public void onNext(RoomOverall roomOverall) {
+                                                    conversation = roomOverall.getOcs().getData();
+                                                    initiateConversation(false);
+                                                }
+
+                                                @Override
+                                                public void onError(Throwable e) {
+                                                    showResultImage(false, false);
+                                                    dispose();
+                                                }
+
+                                                @Override
+                                                public void onComplete() {
+
+                                                }
+                                            });
                                 } else {
                                     initiateConversation(false);
                                 }
@@ -668,6 +697,8 @@ public class OperationsMenuController extends BaseController {
         @Override
         public void onNext(Object o) {
             if (operationCode != 99) {
+                RoomOverall roomOverall = (RoomOverall) o;
+                conversation = roomOverall.getOcs().getData();
                 showResultImage(true, false);
             } else {
                 RoomOverall roomOverall = (RoomOverall) o;
diff --git a/app/src/main/java/com/nextcloud/talk/models/json/chat/ChatMessage.java b/app/src/main/java/com/nextcloud/talk/models/json/chat/ChatMessage.java
index 8e4dba56d..b13ff44cd 100644
--- a/app/src/main/java/com/nextcloud/talk/models/json/chat/ChatMessage.java
+++ b/app/src/main/java/com/nextcloud/talk/models/json/chat/ChatMessage.java
@@ -214,12 +214,16 @@ public class ChatMessage implements IMessage, MessageContentType, MessageContent
         return new IUser() {
             @Override
             public String getId() {
-                return actorId;
+                return actorType + "/" + actorId;
             }
 
             @Override
             public String getName() {
-                return actorDisplayName;
+                if (!TextUtils.isEmpty(actorDisplayName)) {
+                    return actorDisplayName;
+                }
+
+                return NextcloudTalkApplication.Companion.getSharedApplication().getString(R.string.nc_guest);
             }
 
             @Override
diff --git a/app/src/main/java/com/nextcloud/talk/models/json/conversations/Conversation.java b/app/src/main/java/com/nextcloud/talk/models/json/conversations/Conversation.java
index bc81ef087..d068c2750 100644
--- a/app/src/main/java/com/nextcloud/talk/models/json/conversations/Conversation.java
+++ b/app/src/main/java/com/nextcloud/talk/models/json/conversations/Conversation.java
@@ -61,6 +61,10 @@ public class Conversation {
     public boolean hasPassword;
     @JsonField(name = "sessionId")
     public String sessionId;
+    @JsonField(name = "actorId")
+    public String actorId;
+    @JsonField(name = "actorType")
+    public String actorType;
     public String password;
     @JsonField(name = "isFavorite")
     public boolean isFavorite;
@@ -180,6 +184,14 @@ public class Conversation {
         return this.participantType;
     }
 
+    public String getActorId() {
+        return actorId;
+    }
+
+    public String getActorType() {
+        return actorType;
+    }
+
     public boolean isHasPassword() {
         return this.hasPassword;
     }
@@ -277,6 +289,14 @@ public class Conversation {
         this.participantType = participantType;
     }
 
+    public void setActorId(String actorId) {
+        this.actorId = actorId;
+    }
+
+    public void setActorType(String actorType) {
+        this.actorType = actorType;
+    }
+
     public void setHasPassword(boolean hasPassword) {
         this.hasPassword = hasPassword;
     }
@@ -399,6 +419,12 @@ public class Conversation {
         if (sessionId != null ? !sessionId.equals(that.sessionId) : that.sessionId != null) {
             return false;
         }
+        if (actorId != null ? !actorId.equals(that.actorId) : that.actorId != null) {
+            return false;
+        }
+        if (actorType != null ? !actorType.equals(that.actorType) : that.actorType != null) {
+            return false;
+        }
         if (password != null ? !password.equals(that.password) : that.password != null) {
             return false;
         }
@@ -441,6 +467,8 @@ public class Conversation {
         result = 31 * result + (int) (lastPing ^ (lastPing >>> 32));
         result = 31 * result + (participants != null ? participants.hashCode() : 0);
         result = 31 * result + (participantType != null ? participantType.hashCode() : 0);
+        result = 31 * result + (actorId != null ? actorId.hashCode() : 0);
+        result = 31 * result + (actorType != null ? actorType.hashCode() : 0);
         result = 31 * result + (hasPassword ? 1 : 0);
         result = 31 * result + (sessionId != null ? sessionId.hashCode() : 0);
         result = 31 * result + (password != null ? password.hashCode() : 0);
@@ -473,6 +501,8 @@ public class Conversation {
                 ", lastPing=" + lastPing +
                 ", participants=" + participants +
                 ", participantType=" + participantType +
+                ", actorId=" + actorId +
+                ", actorType=" + actorType +
                 ", hasPassword=" + hasPassword +
                 ", sessionId='" + sessionId + '\'' +
                 ", password='" + password + '\'' +