diff --git a/Octokit/Helpers/ConcurrentCache.cs b/Octokit/Helpers/ConcurrentCache.cs
deleted file mode 100644
index 55e6d3d2..00000000
--- a/Octokit/Helpers/ConcurrentCache.cs
+++ /dev/null
@@ -1,39 +0,0 @@
-#if PORTABLE
-using System;
-using System.Collections.Generic;
-using System.Threading;
-
-namespace Octokit
-{
-    /// <summary>
-    /// This is in lieu of ConcurrentDictionary. PCL runtime, specifically windows phone 8 
-    /// does not have access to ConcurrentDictionary. We just use a lock.
-    /// </summary>
-    /// <typeparam name="TKey"></typeparam>
-    /// <typeparam name="TValue"></typeparam>
-    [Obsolete("This component is no longer used, and will be removed in a future update")]
-    public class ConcurrentCache<TKey, TValue>
-    {
-        Dictionary<TKey, TValue> _cache = new Dictionary<TKey, TValue>();
-
-        public TValue GetOrAdd(TKey key, Func<TKey, TValue> valueFactory)
-        {
-            //cannot be null
-            if (valueFactory == null)
-                throw new ArgumentNullException("valueFactory");
-
-            lock (_cache) 
-            {
-                if (_cache.ContainsKey(key)) 
-                {
-                    return _cache[key];
-                }
-
-                var ret = valueFactory(key);
-                _cache[key] = ret;
-                return ret;
-            }
-        }
-    }
-}
-#endif
\ No newline at end of file
diff --git a/Octokit/Http/HttpClientAdapter.cs b/Octokit/Http/HttpClientAdapter.cs
index 61e5b9cb..6a870ebf 100644
--- a/Octokit/Http/HttpClientAdapter.cs
+++ b/Octokit/Http/HttpClientAdapter.cs
@@ -31,7 +31,7 @@ namespace Octokit.Internal
 
 #if HAS_SERVICEPOINTMANAGER
             // GitHub API requires TLS1.2 as of February 2018
-            // 
+            //
             // .NET Framework before 4.6 did not enable TLS1.2 by default
             //
             // Even though this is an AppDomain wide setting, the decision was made for Octokit to
@@ -99,7 +99,7 @@ namespace Octokit.Internal
             object responseBody = null;
             string contentType = null;
 
-            // We added support for downloading images,zip-files and application/octet-stream. 
+            // We added support for downloading images,zip-files and application/octet-stream.
             // Let's constrain this appropriately.
             var binaryContentTypes = new[] {
                 AcceptHeaders.RawContentMediaType,
diff --git a/Octokit/Http/HttpMessageHandlerFactory.cs b/Octokit/Http/HttpMessageHandlerFactory.cs
index 5b9321c8..866d0540 100644
--- a/Octokit/Http/HttpMessageHandlerFactory.cs
+++ b/Octokit/Http/HttpMessageHandlerFactory.cs
@@ -19,17 +19,18 @@ namespace Octokit.Internal
             {
                 AllowAutoRedirect = false
             };
-#if !PORTABLE
+
             if (handler.SupportsAutomaticDecompression)
             {
                 handler.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
             }
+
             if (handler.SupportsProxy && proxy != null)
             {
                 handler.UseProxy = true;
                 handler.Proxy = proxy;
             }
-#endif
+
             return handler;
         }
     }
diff --git a/Octokit/Models/Request/RequestParameters.cs b/Octokit/Models/Request/RequestParameters.cs
index de82010d..5e184c7a 100644
--- a/Octokit/Models/Request/RequestParameters.cs
+++ b/Octokit/Models/Request/RequestParameters.cs
@@ -1,13 +1,11 @@
 using System;
 using System.Collections.Generic;
+using System.Collections.Concurrent;
 using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Linq;
 using System.Reflection;
 using Octokit.Internal;
-#if !PORTABLE
-using System.Collections.Concurrent;
-#endif
 
 namespace Octokit
 {
@@ -16,13 +14,9 @@ namespace Octokit
     /// </summary>
     public abstract class RequestParameters
     {
-#if PORTABLE
-        static readonly ConcurrentCache<Type, List<PropertyParameter>> _propertiesMap =
-            new ConcurrentCache<Type, List<PropertyParameter>>();
-#else
         static readonly ConcurrentDictionary<Type, List<PropertyParameter>> _propertiesMap =
             new ConcurrentDictionary<Type, List<PropertyParameter>>();
-#endif
+
         /// <summary>
         /// Converts the derived object into a dictionary that can be used to supply query string parameters.
         /// </summary>