diff --git a/OpenSim/Services/AuthenticationService/AuthenticationService.cs b/OpenSim/Services/AuthenticationService/AuthenticationService.cs
index 3e6c3b22f2..b81a00486c 100644
--- a/OpenSim/Services/AuthenticationService/AuthenticationService.cs
+++ b/OpenSim/Services/AuthenticationService/AuthenticationService.cs
@@ -83,6 +83,8 @@ namespace OpenSim.Services.AuthenticationService
 
                 m_PerformAuthentication = authConfig.GetBoolean("Authenticate", true);
                 m_AuthorityURL = "http://" + authConfig.GetString("Authority", "localhost");
+                if (!m_AuthorityURL.EndsWith("/"))
+                    m_AuthorityURL += "/";
             }
 
             //