diff --git a/src/Microsoft.AspNet.Server.Kestrel/Infrastructure/TaskUtilities.cs b/src/Microsoft.AspNet.Server.Kestrel/Infrastructure/TaskUtilities.cs
index 6a56e7507a..c0c4c11acc 100644
--- a/src/Microsoft.AspNet.Server.Kestrel/Infrastructure/TaskUtilities.cs
+++ b/src/Microsoft.AspNet.Server.Kestrel/Infrastructure/TaskUtilities.cs
@@ -7,7 +7,7 @@ namespace Microsoft.AspNet.Server.Kestrel.Infrastructure
 {
     public static class TaskUtilities
     {
-#if DOTNET5_4 || DNXCORE50
+#if DOTNET5_4
         public static Task CompletedTask = Task.CompletedTask;
 #else
         public static Task CompletedTask = Task.FromResult<object>(null);
diff --git a/src/Microsoft.AspNet.Server.Kestrel/Networking/Libuv.cs b/src/Microsoft.AspNet.Server.Kestrel/Networking/Libuv.cs
index 2f6a74fced..abe9aa1d56 100644
--- a/src/Microsoft.AspNet.Server.Kestrel/Networking/Libuv.cs
+++ b/src/Microsoft.AspNet.Server.Kestrel/Networking/Libuv.cs
@@ -12,12 +12,7 @@ namespace Microsoft.AspNet.Server.Kestrel.Networking
         {
             IsWindows = PlatformApis.IsWindows;
 
-            var isDarwinMono =
-#if DNX451
-                IsWindows ? false : PlatformApis.IsDarwin;
-#else
-                false;
-#endif
+            var isDarwinMono = PlatformApis.IsDarwin && PlatformApis.IsMono;
 
             if (isDarwinMono)
             {
diff --git a/src/Microsoft.AspNet.Server.Kestrel/Networking/PlatformApis.cs b/src/Microsoft.AspNet.Server.Kestrel/Networking/PlatformApis.cs
index 6117520b3f..a1915ff372 100644
--- a/src/Microsoft.AspNet.Server.Kestrel/Networking/PlatformApis.cs
+++ b/src/Microsoft.AspNet.Server.Kestrel/Networking/PlatformApis.cs
@@ -3,6 +3,7 @@
 
 using System;
 using System.Runtime.InteropServices;
+using Microsoft.Extensions.PlatformAbstractions;
 
 namespace Microsoft.AspNet.Server.Kestrel.Networking
 {
@@ -10,7 +11,7 @@ namespace Microsoft.AspNet.Server.Kestrel.Networking
     {
         static PlatformApis()
         {
-#if DOTNET5_4 || DNXCORE50
+#if DOTNET5_4
             IsWindows = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
             IsDarwin = RuntimeInformation.IsOSPlatform(OSPlatform.OSX);
 #else
@@ -24,12 +25,16 @@ namespace Microsoft.AspNet.Server.Kestrel.Networking
                 IsDarwin = string.Equals(GetUname(), "Darwin", StringComparison.Ordinal);
             }
 #endif
+
+            IsMono = PlatformServices.Default.Runtime.RuntimeType == "Mono";
         }
 
         public static bool IsWindows { get; }
 
         public static bool IsDarwin { get; }
 
+        public static bool IsMono { get; }
+
         [DllImport("libc")]
         static extern int uname(IntPtr buf);
 
diff --git a/src/Microsoft.AspNet.Server.Kestrel/compiler/preprocess/SPCM.cs b/src/Microsoft.AspNet.Server.Kestrel/compiler/preprocess/SPCM.cs
deleted file mode 100644
index df92e585fc..0000000000
--- a/src/Microsoft.AspNet.Server.Kestrel/compiler/preprocess/SPCM.cs
+++ /dev/null
@@ -1,6 +0,0 @@
-namespace Microsoft.AspNet.Server.Kestrel
-{
-    public class StandardsPoliceCompileModule : Microsoft.StandardsPolice.StandardsPoliceCompileModule
-    {
-    }
-}
diff --git a/src/Microsoft.AspNet.Server.Kestrel/project.json b/src/Microsoft.AspNet.Server.Kestrel/project.json
index 2e0caab7c0..4cb8e6bd5d 100644
--- a/src/Microsoft.AspNet.Server.Kestrel/project.json
+++ b/src/Microsoft.AspNet.Server.Kestrel/project.json
@@ -8,6 +8,7 @@
   "dependencies": {
     "Microsoft.AspNet.Hosting": "1.0.0-*",
     "Microsoft.Extensions.Logging.Abstractions": "1.0.0-*",
+    "Microsoft.Extensions.PlatformAbstractions": "1.0.0-*",
     "System.Numerics.Vectors": "4.1.1-*",
     "Microsoft.StandardsPolice": {
       "version": "1.0.0-*",
@@ -24,28 +25,7 @@
     "System.Threading.Tasks.Extensions": "4.0.0-*"
   },
   "frameworks": {
-    "dnx451": { },
     "net451": { },
-    "dnxcore50": {
-      "dependencies": {
-        "System.Collections": "4.0.11-*",
-        "System.Diagnostics.Debug": "4.0.11-*",
-        "System.Diagnostics.TraceSource": "4.0.0-*",
-        "System.Diagnostics.Tracing": "4.0.21-*",
-        "System.Globalization": "4.0.11-*",
-        "System.IO": "4.0.11-*",
-        "System.Linq": "4.0.1-*",
-        "System.Net.Primitives": "4.0.11-*",
-        "System.Runtime.Extensions": "4.0.11-*",
-        "System.Runtime.InteropServices": "4.0.21-*",
-        "System.Text.Encoding": "4.0.11-*",
-        "System.Threading": "4.0.11-*",
-        "System.Threading.Tasks": "4.0.11-*",
-        "System.Threading.Thread": "4.0.0-*",
-        "System.Threading.ThreadPool": "4.0.10-*",
-        "System.Threading.Timer": "4.0.1-*"
-      }
-    },
     "dotnet5.4": {
       "dependencies": {
         "System.Collections": "4.0.11-*",