diff --git a/src/Microsoft.AspNet.SignalR.Core/Hubs/Lookup/ReflectedHubDescriptorProvider.cs b/src/Microsoft.AspNet.SignalR.Core/Hubs/Lookup/ReflectedHubDescriptorProvider.cs
index 705a31c1d6..fe075431f2 100644
--- a/src/Microsoft.AspNet.SignalR.Core/Hubs/Lookup/ReflectedHubDescriptorProvider.cs
+++ b/src/Microsoft.AspNet.SignalR.Core/Hubs/Lookup/ReflectedHubDescriptorProvider.cs
@@ -40,7 +40,7 @@ public bool TryGetHub(string hubName, out HubDescriptor descriptor)
             return _hubs.Value.TryGetValue(hubName, out descriptor);
         }
 
-        protected IDictionary<string, HubDescriptor> BuildHubsCache()
+        protected virtual IDictionary<string, HubDescriptor> BuildHubsCache()
         {
             // Getting all IHub-implementing types that apply
             var types = _locator.Value.GetAssemblies()
diff --git a/src/Microsoft.AspNet.SignalR.Core/Owin/OwinExtensions.cs b/src/Microsoft.AspNet.SignalR.Core/Owin/OwinExtensions.cs
index 19cadc05c4..67066999bd 100644
--- a/src/Microsoft.AspNet.SignalR.Core/Owin/OwinExtensions.cs
+++ b/src/Microsoft.AspNet.SignalR.Core/Owin/OwinExtensions.cs
@@ -53,7 +53,7 @@ public static IAppBuilder MapSignalR(this IAppBuilder builder, string path, HubC
         {
             if (configuration == null)
             {
-                throw new ArgumentNullException("configuration");
+                throw new ArgumentNullException(nameof(configuration));
             }
 
             return builder.Map(path, subApp => subApp.RunSignalR(configuration));
@@ -118,7 +118,7 @@ public static IAppBuilder MapSignalR(this IAppBuilder builder, string path, Type
         {
             if (configuration == null)
             {
-                throw new ArgumentNullException("configuration");
+                throw new ArgumentNullException(nameof(configuration));
             }
 
             return builder.Map(path, subApp => subApp.RunSignalR(connectionType, configuration));