diff --git a/mdoc/Mono.Documentation/Updater/DocUtils.cs b/mdoc/Mono.Documentation/Updater/DocUtils.cs
index 13bfc423..aee12b6e 100644
--- a/mdoc/Mono.Documentation/Updater/DocUtils.cs
+++ b/mdoc/Mono.Documentation/Updater/DocUtils.cs
@@ -452,9 +452,8 @@ public static IEnumerable<TypeReference> GetUserImplementedInterfaces (TypeDefin
             foreach (var ii in type.Interfaces)
             {
                 var iface = ii.InterfaceType;
-                TypeReference lookup = iface.Resolve () ?? iface;
 
-                var iname = GetQualifiedTypeName(lookup);
+                var iname = GetQualifiedTypeName(iface);
 
                 if (!inheritedInterfaces.Contains (iname))
                     userInterfaces.Add (iface);