diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/ui/AddAccountPane.java b/HMCL/src/main/java/org/jackhuang/hmcl/ui/AddAccountPane.java
index 1b66d1f4c..87d2111ed 100644
--- a/HMCL/src/main/java/org/jackhuang/hmcl/ui/AddAccountPane.java
+++ b/HMCL/src/main/java/org/jackhuang/hmcl/ui/AddAccountPane.java
@@ -152,8 +152,9 @@ public class AddAccountPane extends StackPane {
                         Accounts.getAccounts().add(account);
                     } else {
                         // adding an already-added account
-                        // instead of discarding the new account, we replace the existing account with the new account
-                        Accounts.getAccounts().set(oldIndex, account);
+                        // instead of discarding the new account, we first remove the existing one then add the new one
+                        Accounts.getAccounts().remove(oldIndex);
+                        Accounts.getAccounts().add(oldIndex, account);
                     }
                     acceptPane.hideSpinner();
                     fireEvent(new DialogCloseEvent());
diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/util/MappedObservableList.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/util/MappedObservableList.java
index da7684e5b..21ab225eb 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/util/MappedObservableList.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/util/MappedObservableList.java
@@ -22,7 +22,7 @@ import static javafx.collections.FXCollections.unmodifiableObservableList;
 
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.HashMap;
+import java.util.IdentityHashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -75,7 +75,7 @@ public final class MappedObservableList {
         @Override
         public void onChanged(Change<? extends T> change) {
             // cache removed elements to reduce calls to mapper
-            Map<T, LinkedList<U>> cache = new HashMap<>();
+            Map<T, LinkedList<U>> cache = new IdentityHashMap<>();
 
             while (change.next()) {
                 int from = change.getFrom();