diff --git a/app/src/main/java/es/wolfi/app/passman/autofill/CredentialAutofillService.java b/app/src/main/java/es/wolfi/app/passman/autofill/CredentialAutofillService.java
index 811046c06..432a608ed 100644
--- a/app/src/main/java/es/wolfi/app/passman/autofill/CredentialAutofillService.java
+++ b/app/src/main/java/es/wolfi/app/passman/autofill/CredentialAutofillService.java
@@ -40,6 +40,7 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.concurrent.CopyOnWriteArrayList;
 
 import es.wolfi.app.ResponseHandlers.AutofillCredentialSaveResponseHandler;
 import es.wolfi.app.passman.R;
@@ -115,7 +116,7 @@ public void onFillRequest(FillRequest request, CancellationSignal cancellationSi
         CredentialAutofillService.WebDomainResult domain = getLikelyDomain(structures);
 
         // Grab Credentials from vault
-        ArrayList<Credential> allCred = v.getCredentials();
+        CopyOnWriteArrayList<Credential> allCred = v.getCredentials();
 
         if (allCred.isEmpty()) {
             Toast.makeText(getApplicationContext(), getString(R.string.autofill_vaultempty), Toast.LENGTH_SHORT).show();
@@ -397,7 +398,7 @@ private String returnBestString(@NonNull String... usernameOptions) {
     }
 
     private List<Credential> findMatchingCredentials(
-            @NonNull ArrayList<Credential> credentialArrayList,
+            @NonNull CopyOnWriteArrayList<Credential> credentialArrayList,
             @NonNull String packageName,
             @NonNull CredentialAutofillService.WebDomainResult domain) {
         ArrayList<Credential> matchingDomainCred = new ArrayList<>();
diff --git a/app/src/main/java/es/wolfi/app/passman/fragments/CredentialItemFragment.java b/app/src/main/java/es/wolfi/app/passman/fragments/CredentialItemFragment.java
index 7ae8ca680..aeb10b919 100644
--- a/app/src/main/java/es/wolfi/app/passman/fragments/CredentialItemFragment.java
+++ b/app/src/main/java/es/wolfi/app/passman/fragments/CredentialItemFragment.java
@@ -39,6 +39,7 @@
 import androidx.recyclerview.widget.RecyclerView;
 
 import java.util.ArrayList;
+import java.util.concurrent.CopyOnWriteArrayList;
 
 import es.wolfi.app.passman.R;
 import es.wolfi.app.passman.SettingValues;
@@ -134,7 +135,7 @@ public void applyFilters(Vault vault, EditText searchInput) {
             filterTask.cancel(true);
         }
         filterTask = new FilterListAsyncTask(searchText, recyclerView, mListener);
-        ArrayList<Credential> input[] = new ArrayList[]{vault.getCredentials()};
+        CopyOnWriteArrayList<Credential> input[] = new CopyOnWriteArrayList[]{vault.getCredentials()};
         filterTask.execute((Object[]) input);
     }
 
diff --git a/app/src/main/java/es/wolfi/passman/API/Vault.java b/app/src/main/java/es/wolfi/passman/API/Vault.java
index ad3dc2009..ebdce0fb7 100644
--- a/app/src/main/java/es/wolfi/passman/API/Vault.java
+++ b/app/src/main/java/es/wolfi/passman/API/Vault.java
@@ -35,6 +35,7 @@
 import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
+import java.util.concurrent.CopyOnWriteArrayList;
 
 import es.wolfi.app.passman.SJCLCrypto;
 import es.wolfi.app.passman.SettingValues;
@@ -51,7 +52,7 @@ public class Vault extends Core implements Filterable {
     public double last_access;
     public String challenge_password;
 
-    ArrayList<Credential> credentials;
+    CopyOnWriteArrayList<Credential> credentials;
     HashMap<String, Integer> credential_guid;
 
     private String encryption_key = "";
@@ -162,7 +163,7 @@ public Date getLastAccessTime() {
         return new Date((long) last_access * 1000);
     }
 
-    public ArrayList<Credential> getCredentials() {
+    public CopyOnWriteArrayList<Credential> getCredentials() {
         return credentials;
     }
 
@@ -227,7 +228,7 @@ public static Vault fromJSON(JSONObject o) throws JSONException {
 
         if (o.has("credentials")) {
             JSONArray j = o.getJSONArray("credentials");
-            v.credentials = new ArrayList<Credential>();
+            v.credentials = new CopyOnWriteArrayList<Credential>();
             v.credential_guid = new HashMap<>();
 
             for (int i = 0; i < j.length(); i++) {
@@ -246,11 +247,16 @@ public static Vault fromJSON(JSONObject o) throws JSONException {
     }
 
     public void sort(int method) {
+        ArrayList<Credential> temp = new ArrayList<>(credentials);
         credential_guid.clear();
-        Collections.sort(credentials, new CredentialLabelSort(method));
-        for (int i = 0; i < credentials.size(); i++) {
-            credential_guid.put(credentials.get(i).getGuid(), i);
+
+        Collections.sort(temp, new CredentialLabelSort(method));
+        for (int i = 0; i < temp.size(); i++) {
+            credential_guid.put(temp.get(i).getGuid(), i);
         }
+
+        credentials.clear();
+        credentials.addAll(temp);
     }
 
     public void addCredential(Credential credential) {
@@ -271,6 +277,8 @@ public void deleteCredential(Credential updatedCredential) {
         for (Credential credential : credentials) {
             if (credential.getGuid().equals(updatedCredential.getGuid())) {
                 credentials.remove(credential);
+                credential_guid.remove(updatedCredential.getGuid());
+                break;
             }
         }
     }
diff --git a/app/src/main/java/es/wolfi/utils/FilterListAsyncTask.java b/app/src/main/java/es/wolfi/utils/FilterListAsyncTask.java
index 01adf7c99..b6def8329 100644
--- a/app/src/main/java/es/wolfi/utils/FilterListAsyncTask.java
+++ b/app/src/main/java/es/wolfi/utils/FilterListAsyncTask.java
@@ -1,23 +1,22 @@
 /**
- *  Passman Android App
+ * Passman Android App
  *
  * @copyright Copyright (c) 2016, Sander Brand (brantje@gmail.com)
  * @copyright Copyright (c) 2016, Marcos Zuriaga Miguel (wolfi@wolfi.es)
  * @license GNU AGPL version 3 or any later version
- *
+ * <p>
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
- *
+ * <p>
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Affero General Public License for more details.
- *
+ * <p>
  * You should have received a copy of the GNU Affero General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
  */
 
 package es.wolfi.utils;
@@ -27,31 +26,31 @@
 
 import androidx.recyclerview.widget.RecyclerView;
 
-import java.util.ArrayList;
+import java.util.concurrent.CopyOnWriteArrayList;
 
-import es.wolfi.app.passman.fragments.CredentialItemFragment;
 import es.wolfi.app.passman.adapters.CredentialViewAdapter;
-import es.wolfi.app.passman.fragments.VaultFragment;
 import es.wolfi.app.passman.adapters.VaultViewAdapter;
+import es.wolfi.app.passman.fragments.CredentialItemFragment;
+import es.wolfi.app.passman.fragments.VaultFragment;
 import es.wolfi.passman.API.Credential;
 import es.wolfi.passman.API.Vault;
 
-public class FilterListAsyncTask <T extends Filterable> extends AsyncTask<ArrayList<T>, Integer, ArrayList<T>>{
+public class FilterListAsyncTask<T extends Filterable> extends AsyncTask<CopyOnWriteArrayList<T>, Integer, CopyOnWriteArrayList<T>> {
 
-    private String filter;
+    private final String filter;
     RecyclerView recyclerView;
     CredentialItemFragment.OnListFragmentInteractionListener credentialMListener = null;
     VaultFragment.OnListFragmentInteractionListener vaultMListener = null;
     Boolean isVaultFragment;
 
-    public FilterListAsyncTask(String filter, RecyclerView recyclerView, CredentialItemFragment.OnListFragmentInteractionListener mListener){
+    public FilterListAsyncTask(String filter, RecyclerView recyclerView, CredentialItemFragment.OnListFragmentInteractionListener mListener) {
         this.filter = filter;
         this.recyclerView = recyclerView;
         this.credentialMListener = mListener;
         this.isVaultFragment = false;
     }
 
-    public FilterListAsyncTask(String filter, RecyclerView recyclerView, VaultFragment.OnListFragmentInteractionListener mListener){
+    public FilterListAsyncTask(String filter, RecyclerView recyclerView, VaultFragment.OnListFragmentInteractionListener mListener) {
         this.filter = filter;
         this.recyclerView = recyclerView;
         this.vaultMListener = mListener;
@@ -59,17 +58,16 @@ public FilterListAsyncTask(String filter, RecyclerView recyclerView, VaultFragme
     }
 
     @Override
-    protected ArrayList<T> doInBackground(ArrayList<T>... list) {
-        return new ListUtils().filterList(filter, list[0]);
+    protected CopyOnWriteArrayList<T> doInBackground(CopyOnWriteArrayList<T>... list) {
+        return ListUtils.filterList(filter, list[0]);
     }
 
     @Override
-    protected void onPostExecute(ArrayList<T> filteredList){
-        if(isVaultFragment){
-            recyclerView.setAdapter(new VaultViewAdapter((ArrayList<Vault>)filteredList, vaultMListener));
-        }
-        else {
-            recyclerView.setAdapter(new CredentialViewAdapter((ArrayList<Credential>) filteredList, credentialMListener, PreferenceManager.getDefaultSharedPreferences(recyclerView.getContext())));
+    protected void onPostExecute(CopyOnWriteArrayList<T> filteredList) {
+        if (isVaultFragment) {
+            recyclerView.setAdapter(new VaultViewAdapter((CopyOnWriteArrayList<Vault>) filteredList, vaultMListener));
+        } else {
+            recyclerView.setAdapter(new CredentialViewAdapter((CopyOnWriteArrayList<Credential>) filteredList, credentialMListener, PreferenceManager.getDefaultSharedPreferences(recyclerView.getContext())));
         }
     }
 }
diff --git a/app/src/main/java/es/wolfi/utils/ListUtils.java b/app/src/main/java/es/wolfi/utils/ListUtils.java
index a0d98794e..9f2583754 100644
--- a/app/src/main/java/es/wolfi/utils/ListUtils.java
+++ b/app/src/main/java/es/wolfi/utils/ListUtils.java
@@ -1,37 +1,34 @@
 /**
- *  Passman Android App
+ * Passman Android App
  *
  * @copyright Copyright (c) 2016, Sander Brand (brantje@gmail.com)
  * @copyright Copyright (c) 2016, Marcos Zuriaga Miguel (wolfi@wolfi.es)
  * @license GNU AGPL version 3 or any later version
- *
+ * <p>
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
- *
+ * <p>
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Affero General Public License for more details.
- *
+ * <p>
  * You should have received a copy of the GNU Affero General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
  */
 
 package es.wolfi.utils;
 
-import java.util.ArrayList;
-import java.util.Iterator;
+import java.util.concurrent.CopyOnWriteArrayList;
 
 public class ListUtils {
-    public static <T extends Filterable> ArrayList<T> filterList(String filter, ArrayList<T> list){
-        ArrayList<T> copiedList = new ArrayList<T>(list);
-        Iterator<T> it = copiedList.iterator();
-        while (it.hasNext()) {
-            if (!it.next().getFilterableAttribute().contains(filter)) {
-                it.remove();
+    public static <T extends Filterable> CopyOnWriteArrayList<T> filterList(String filter, CopyOnWriteArrayList<T> list) {
+        CopyOnWriteArrayList<T> copiedList = new CopyOnWriteArrayList<T>();
+        for (T item : list) {
+            if (item.getFilterableAttribute().contains(filter)) {
+                copiedList.add(item);
             }
         }
         return copiedList;