diff --git a/BunqSdk/Model/Core/OauthAccessToken.cs b/BunqSdk/Model/Core/OauthAccessToken.cs
index 6851d61..d0d5fa4 100644
--- a/BunqSdk/Model/Core/OauthAccessToken.cs
+++ b/BunqSdk/Model/Core/OauthAccessToken.cs
@@ -32,7 +32,7 @@ public class OauthAccessToken : BunqModel
         /// <summary>
         /// Token constants.
         /// </summary>
-        protected const String TOKEN_URI_FORMAT_SANDBOX = "https://api.oauth.sandbox.bunq.com/v1/token?{0}";
+        protected const String TOKEN_URI_FORMAT_SANDBOX = "https://api-oauth.sandbox.bunq.com/v1/token?{0}";
         protected const String TOKEN_URI_FORMAT_PRODUCTION = "https://api.oauth.bunq.com/v1/token?{0}";
         
         [JsonProperty(PropertyName = "access_token")]
@@ -125,4 +125,4 @@ private static String DetermineTokenUriFormat()
             return TOKEN_URI_FORMAT_MAP[BunqContext.ApiContext.EnvironmentType.TypeString];
         }
     }
-}
\ No newline at end of file
+}