diff --git a/Assets/UnityGoogleDrive/Editor/GoogleDriveSettingsEditor.cs b/Assets/UnityGoogleDrive/Editor/GoogleDriveSettingsEditor.cs
index 856c2c0..ede3126 100644
--- a/Assets/UnityGoogleDrive/Editor/GoogleDriveSettingsEditor.cs
+++ b/Assets/UnityGoogleDrive/Editor/GoogleDriveSettingsEditor.cs
@@ -14,6 +14,7 @@ public class GoogleDriveSettingsEditor : Editor
         private SerializedProperty uriSchemeClientCredentials;
         private SerializedProperty accessScopes;
         private SerializedProperty loopbackUri;
+        private SerializedProperty loopbackPort;
         private SerializedProperty loopbackResponseHtml;
         private SerializedProperty accessTokenPrefsKey;
         private SerializedProperty refreshTokenPrefsKey;
@@ -21,7 +22,8 @@ public class GoogleDriveSettingsEditor : Editor
         private static readonly GUIContent genericClientCredentialsContent = new GUIContent("Generic Credentials", "Google Drive API application credentials used to authorize requests via loopback and redirect schemes.");
         private static readonly GUIContent uriSchemeClientCredentialsContent = new GUIContent("URI Scheme Credentials", "Google Drive API application credentials used to authorize requests via custom URI scheme.");
         private static readonly GUIContent accessScopesContent = new GUIContent("Access Scopes", "Scopes of access to the user's Google Drive the app will request.");
-        private static readonly GUIContent loopbackUriContent = new GUIContent("Loopback URI", "A web address for the loopback authentication requests. Defult is 'localhost'.");
+        private static readonly GUIContent loopbackUriContent = new GUIContent("Loopback URI", "A web address for the loopback authentication requests. Default is 'localhost'.");
+        private static readonly GUIContent loopbackPortContent = new GUIContent("Loopback Port", "Specific port to use for loopback scheme, eg: 8888. Leave empty to find random unused port.");
         private static readonly GUIContent loopbackResponseHtmlContent = new GUIContent("Loopback Response HTML", "HTML page shown to the user when loopback response is received.");
         private static readonly GUIContent accessTokenPrefsKeyContent = new GUIContent("Access Token Key", "PlayerPrefs key used to store access token.");
         private static readonly GUIContent refreshTokenPrefsKeyContent = new GUIContent("Refresh Token Key", "PlayerPrefs key used to store refresh token.");
@@ -59,6 +61,7 @@ private void OnEnable ()
             uriSchemeClientCredentials = serializedObject.FindProperty("uriSchemeClientCredentials");
             accessScopes = serializedObject.FindProperty("accessScopes");
             loopbackUri = serializedObject.FindProperty("loopbackUri");
+            loopbackPort = serializedObject.FindProperty("loopbackPort");
             loopbackResponseHtml = serializedObject.FindProperty("loopbackResponseHtml");
             accessTokenPrefsKey = serializedObject.FindProperty("accessTokenPrefsKey");
             refreshTokenPrefsKey = serializedObject.FindProperty("refreshTokenPrefsKey");
@@ -76,6 +79,7 @@ public override void OnInspectorGUI ()
             EditorGUILayout.PropertyField(uriSchemeClientCredentials, uriSchemeClientCredentialsContent, true);
             EditorGUILayout.PropertyField(accessScopes, accessScopesContent, true);
             EditorGUILayout.PropertyField(loopbackUri, loopbackUriContent);
+            EditorGUILayout.PropertyField(loopbackPort, loopbackPortContent);
             EditorGUILayout.PropertyField(loopbackResponseHtml, loopbackResponseHtmlContent);
             EditorGUILayout.PropertyField(accessTokenPrefsKey, accessTokenPrefsKeyContent);
             EditorGUILayout.PropertyField(refreshTokenPrefsKey, refreshTokenPrefsKeyContent);
@@ -87,8 +91,7 @@ public override void OnInspectorGUI ()
 
             using (new EditorGUI.DisabledScope(string.IsNullOrEmpty(TargetSettings.GenericClientCredentials.ProjectId)))
                 if (GUILayout.Button("Manage Google Drive API app"))
-                    Application.OpenURL(string.Format("https://console.developers.google.com/apis/credentials?project={0}",
-                        TargetSettings.GenericClientCredentials.ProjectId));
+                    Application.OpenURL($"https://console.developers.google.com/apis/credentials?project={TargetSettings.GenericClientCredentials.ProjectId}");
 
             if (GUILayout.Button("Parse generic credentials JSON file..."))
                 ParseGenericCredentialsJson(EditorUtility.OpenFilePanel("Select Drive API app credentials JSON file", "", "json"));
diff --git a/Assets/UnityGoogleDrive/Runtime/Authorization/LoopbackAccessTokenProvider.cs b/Assets/UnityGoogleDrive/Runtime/Authorization/LoopbackAccessTokenProvider.cs
index c895eb0..da17954 100644
--- a/Assets/UnityGoogleDrive/Runtime/Authorization/LoopbackAccessTokenProvider.cs
+++ b/Assets/UnityGoogleDrive/Runtime/Authorization/LoopbackAccessTokenProvider.cs
@@ -104,7 +104,9 @@ private void ExecuteFullAuth ()
             var codeChallenge = CryptoUtils.Base64UriEncodeNoPadding(codeVerifierHash);
 
             // Creates a redirect URI using an available port on the loopback address.
-            redirectUri = $"{settings.LoopbackUri}:{GetRandomUnusedPort()}";
+            var port = string.IsNullOrWhiteSpace(settings.LoopbackPort)
+                ? GetRandomUnusedPort() : int.Parse(settings.LoopbackPort);
+            redirectUri = $"{settings.LoopbackUri}:{port}";
 
             // Listen for requests on the redirect URI.
             var httpListener = new HttpListener();
@@ -113,9 +115,10 @@ private void ExecuteFullAuth ()
 
             // Create the OAuth 2.0 authorization request.
             // https://developers.google.com/identity/protocols/OAuth2WebServer#creatingclient
-            var authRequest = string.Format("{0}?response_type=code&scope={1}&redirect_uri={2}&client_id={3}&state={4}&code_challenge={5}&code_challenge_method={6}" +
-                    "&access_type=offline" + // Forces to return a refresh token at the auth code exchange phase.
-                    "&approval_prompt=force", // Forces to show consent screen for each auth request. Needed to return refresh tokens on consequent auth runs.
+            var authRequest = string.Format(
+                "{0}?response_type=code&scope={1}&redirect_uri={2}&client_id={3}&state={4}&code_challenge={5}&code_challenge_method={6}" +
+                "&access_type=offline" + // Forces to return a refresh token at the auth code exchange phase.
+                "&approval_prompt=force", // Forces to show consent screen for each auth request. Needed to return refresh tokens on consequent auth runs.
                 settings.GenericClientCredentials.AuthUri,
                 Uri.EscapeDataString(settings.AccessScope),
                 Uri.EscapeDataString(redirectUri),
diff --git a/Assets/UnityGoogleDrive/Runtime/GoogleDriveSettings.cs b/Assets/UnityGoogleDrive/Runtime/GoogleDriveSettings.cs
index 471a38f..9e8ac5e 100644
--- a/Assets/UnityGoogleDrive/Runtime/GoogleDriveSettings.cs
+++ b/Assets/UnityGoogleDrive/Runtime/GoogleDriveSettings.cs
@@ -35,6 +35,10 @@ public class GoogleDriveSettings : ScriptableObject
         /// <see href="https://forum.unity.com/threads/515360/page-2#post-3504547"/>
         public string LoopbackUri => loopbackUri;
         /// <summary>
+        /// Specific port to use for loopback scheme. When empty find random unused port instead.
+        /// </summary>
+        public string LoopbackPort => loopbackPort;
+        /// <summary>
         /// HTML page shown to the user when loopback response is received.
         /// </summary>
         public string LoopbackResponseHtml { get => loopbackResponseHtml; set => loopbackResponseHtml = value; }
@@ -51,6 +55,7 @@ public class GoogleDriveSettings : ScriptableObject
         [SerializeField] private UriSchemeClientCredentials uriSchemeClientCredentials;
         [SerializeField] private List<string> accessScopes = new List<string> { "https://www.googleapis.com/auth/drive", "https://www.googleapis.com/auth/drive.appdata" };
         [SerializeField] private string loopbackUri = "http://localhost";
+        [SerializeField] private string loopbackPort = "";
         [SerializeField] private string loopbackResponseHtml = "<html><h1>Please return to the app.</h1></html>";
         [SerializeField] private string accessTokenPrefsKey = "GoogleDriveAccessToken";
         [SerializeField] private string refreshTokenPrefsKey = "GoogleDriveRefreshToken";
diff --git a/Assets/UnityGoogleDrive/package.json b/Assets/UnityGoogleDrive/package.json
index e387c36..5f2890f 100644
--- a/Assets/UnityGoogleDrive/package.json
+++ b/Assets/UnityGoogleDrive/package.json
@@ -1,6 +1,6 @@
 {
     "name": "com.elringus.unitygoogledrive",
-    "version": "0.28.0",
+    "version": "0.29.0",
     "displayName": "UnityGoogleDrive",
     "description": "Google Drive SDK for Unity game engine",
     "unity": "2019.4",
diff --git a/UnityGoogleDrive.unitypackage b/UnityGoogleDrive.unitypackage
index d000afb..f6cb634 100644
Binary files a/UnityGoogleDrive.unitypackage and b/UnityGoogleDrive.unitypackage differ