diff --git a/src/main/java/eu/siacs/conversations/entities/MucOptions.java b/src/main/java/eu/siacs/conversations/entities/MucOptions.java
index f2231178e..a92cb6768 100644
--- a/src/main/java/eu/siacs/conversations/entities/MucOptions.java
+++ b/src/main/java/eu/siacs/conversations/entities/MucOptions.java
@@ -101,8 +101,9 @@ public class MucOptions {
         return tookProposedNickFromBookmark;
     }
 
-    void notifyOfBookmarkNick(String nick) {
-        if (nick != null && nick.trim().equals(getSelf().getFullJid().getResource())) {
+    void notifyOfBookmarkNick(final String nick) {
+        final String normalized = normalize(account.getJid(),nick);
+        if (normalized != null && normalized.equals(getSelf().getFullJid().getResource())) {
             this.tookProposedNickFromBookmark = true;
         }
     }
@@ -389,15 +390,15 @@ public class MucOptions {
 
     private String getProposedNick() {
         final Bookmark bookmark = this.conversation.getBookmark();
-        final String bookmarkedNick = bookmark == null ? null : bookmark.getNick();
-        if (bookmarkedNick != null && !bookmarkedNick.trim().isEmpty()) {
+        final String bookmarkedNick = normalize(account.getJid(), bookmark == null ? null : bookmark.getNick());
+        if (bookmarkedNick != null) {
             this.tookProposedNickFromBookmark = true;
-            return bookmarkedNick.trim();
+            return bookmarkedNick;
         } else if (!conversation.getJid().isBareJid()) {
             return conversation.getJid().getResource();
         } else {
-            final String displayName = account.getDisplayName();
-            if (TextUtils.isEmpty(displayName)) {
+            final String displayName = normalize(account.getJid(), account.getDisplayName());
+            if (displayName == null) {
                 return JidHelper.localPartOrFallback(account.getJid());
             } else {
                 return displayName;
@@ -405,6 +406,18 @@ public class MucOptions {
         }
     }
 
+    private static String normalize(Jid account, String nick) {
+        if (account == null || TextUtils.isEmpty(nick)) {
+            return null;
+        }
+        try {
+            return account.withResource(nick).getResource();
+        } catch (IllegalArgumentException e) {
+            return null;
+        }
+
+    }
+
     public String getActualNick() {
         if (this.self.getName() != null) {
             return this.self.getName();
@@ -532,7 +545,7 @@ public class MucOptions {
 
     public Jid createJoinJid(String nick) {
         try {
-            return Jid.of(this.conversation.getJid().asBareJid().toString() + "/" + nick);
+            return conversation.getJid().withResource(nick);
         } catch (final IllegalArgumentException e) {
             return null;
         }
@@ -590,6 +603,7 @@ public class MucOptions {
 
         private int resId;
         private int rank;
+
         Affiliation(int rank, int resId) {
             this.resId = resId;
             this.rank = rank;
@@ -632,6 +646,7 @@ public class MucOptions {
 
         private int resId;
         private int rank;
+
         Role(int resId, int rank) {
             this.resId = resId;
             this.rank = rank;