diff --git a/src/Microsoft.AspNetCore.Http.Abstractions/project.json b/src/Microsoft.AspNetCore.Http.Abstractions/project.json
index 95ff47a821..bfef7f3f63 100644
--- a/src/Microsoft.AspNetCore.Http.Abstractions/project.json
+++ b/src/Microsoft.AspNetCore.Http.Abstractions/project.json
@@ -15,6 +15,7 @@
       "type": "build",
       "version": "1.0.0-*"
     },
+    "Microsoft.NETCore.Platforms": "1.0.1-*",
     "System.Text.Encodings.Web": "4.0.0-*"
   },
   "frameworks": {
@@ -33,7 +34,8 @@
         "System.Reflection.TypeExtensions": "4.1.0-*",
         "System.Runtime.InteropServices": "4.0.21-*",
         "System.Security.Cryptography.X509Certificates": "4.0.0-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   }
 }
diff --git a/src/Microsoft.AspNetCore.Http.Extensions/project.json b/src/Microsoft.AspNetCore.Http.Extensions/project.json
index f38f4a0f48..628312a5dc 100644
--- a/src/Microsoft.AspNetCore.Http.Extensions/project.json
+++ b/src/Microsoft.AspNetCore.Http.Extensions/project.json
@@ -12,6 +12,7 @@
   "dependencies": {
     "Microsoft.AspNetCore.Http.Abstractions": "1.0.0-*",
     "Microsoft.Net.Http.Headers": "1.0.0-*",
+    "Microsoft.NETCore.Platforms": "1.0.1-*",
     "System.Buffers": "4.0.0-*"
   },
   "frameworks": {
@@ -19,7 +20,8 @@
     "dotnet5.4": {
       "dependencies": {
         "System.IO.FileSystem": "4.0.1-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   }
 }
diff --git a/src/Microsoft.AspNetCore.Http.Features/project.json b/src/Microsoft.AspNetCore.Http.Features/project.json
index 0ccf00e18b..e1da5dee1d 100644
--- a/src/Microsoft.AspNetCore.Http.Features/project.json
+++ b/src/Microsoft.AspNetCore.Http.Features/project.json
@@ -10,7 +10,8 @@
     "keyFile": "../../tools/Key.snk"
   },
   "dependencies": {
-    "Microsoft.Extensions.Primitives": "1.0.0-*"
+    "Microsoft.Extensions.Primitives": "1.0.0-*",
+    "Microsoft.NETCore.Platforms": "1.0.1-*"
   },
   "frameworks": {
     "net451": {},
@@ -24,7 +25,8 @@
         "System.Security.Claims": "4.0.1-*",
         "System.Security.Cryptography.X509Certificates": "4.0.0-*",
         "System.Security.Principal": "4.0.1-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   }
 }
diff --git a/src/Microsoft.AspNetCore.Http/project.json b/src/Microsoft.AspNetCore.Http/project.json
index 728e38ebcc..ca15e09a6a 100644
--- a/src/Microsoft.AspNetCore.Http/project.json
+++ b/src/Microsoft.AspNetCore.Http/project.json
@@ -13,14 +13,16 @@
   "dependencies": {
     "Microsoft.AspNetCore.Http.Abstractions": "1.0.0-*",
     "Microsoft.AspNetCore.WebUtilities": "1.0.0-*",
-    "Microsoft.Net.Http.Headers": "1.0.0-*"
+    "Microsoft.Net.Http.Headers": "1.0.0-*",
+    "Microsoft.NETCore.Platforms": "1.0.1-*"
   },
   "frameworks": {
     "net451": {},
     "dotnet5.4": {
       "dependencies": {
         "System.Threading":  "4.0.11-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   }
 }
diff --git a/src/Microsoft.AspNetCore.Owin/project.json b/src/Microsoft.AspNetCore.Owin/project.json
index 4a02e2515c..a9b4137b4a 100644
--- a/src/Microsoft.AspNetCore.Owin/project.json
+++ b/src/Microsoft.AspNetCore.Owin/project.json
@@ -10,10 +10,13 @@
     "keyFile": "../../tools/Key.snk"
   },
   "dependencies": {
-    "Microsoft.AspNetCore.Http": "1.0.0-*"
+    "Microsoft.AspNetCore.Http": "1.0.0-*",
+    "Microsoft.NETCore.Platforms": "1.0.1-*"
   },
   "frameworks": {
     "net451": {},
-    "dotnet5.4": {}
+    "dotnet5.4": {
+      "imports": "portable-net451+win8"
+    }
   }
 }
diff --git a/src/Microsoft.AspNetCore.WebUtilities/project.json b/src/Microsoft.AspNetCore.WebUtilities/project.json
index 9ff39f4337..67191b79c7 100644
--- a/src/Microsoft.AspNetCore.WebUtilities/project.json
+++ b/src/Microsoft.AspNetCore.WebUtilities/project.json
@@ -11,6 +11,7 @@
   },
   "dependencies": {
     "Microsoft.Extensions.Primitives": "1.0.0-*",
+    "Microsoft.NETCore.Platforms": "1.0.1-*",
     "System.Buffers": "4.0.0-*",
     "System.Text.Encodings.Web": "4.0.0-*"
   },
@@ -25,7 +26,8 @@
         "System.Collections": "4.0.11-*",
         "System.IO": "4.1.0-*",
         "System.IO.FileSystem": "4.0.1-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   }
 }
diff --git a/src/Microsoft.Net.Http.Headers/project.json b/src/Microsoft.Net.Http.Headers/project.json
index 311e571a11..a8287db73f 100644
--- a/src/Microsoft.Net.Http.Headers/project.json
+++ b/src/Microsoft.Net.Http.Headers/project.json
@@ -9,6 +9,9 @@
     "warningsAsErrors": true,
     "keyFile": "../../tools/Key.snk"
   },
+  "dependencies": {
+    "Microsoft.NETCore.Platforms": "1.0.1-*"
+  },
   "frameworks": {
     "net451": {},
     "dotnet5.4": {
@@ -20,7 +23,8 @@
         "System.Linq": "4.0.1-*",
         "System.Text.Encoding": "4.0.11-*",
         "System.Runtime": "4.0.21-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   }
 }
diff --git a/test/Microsoft.AspNetCore.Http.Abstractions.Tests/project.json b/test/Microsoft.AspNetCore.Http.Abstractions.Tests/project.json
index 3814325f09..4960e47a3a 100644
--- a/test/Microsoft.AspNetCore.Http.Abstractions.Tests/project.json
+++ b/test/Microsoft.AspNetCore.Http.Abstractions.Tests/project.json
@@ -21,7 +21,8 @@
     "dnxcore50": { 
       "dependencies": {
         "xunit.runner.aspnet": "2.0.0-aspnet-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   },
   "testRunner": "xunit",
diff --git a/test/Microsoft.AspNetCore.Http.Extensions.Tests/project.json b/test/Microsoft.AspNetCore.Http.Extensions.Tests/project.json
index 6d81867330..8943eb081f 100644
--- a/test/Microsoft.AspNetCore.Http.Extensions.Tests/project.json
+++ b/test/Microsoft.AspNetCore.Http.Extensions.Tests/project.json
@@ -18,7 +18,8 @@
     "dnxcore50": { 
       "dependencies": {
         "xunit.runner.aspnet": "2.0.0-aspnet-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   },
   "testRunner": "xunit",
diff --git a/test/Microsoft.AspNetCore.Http.Features.Tests/project.json b/test/Microsoft.AspNetCore.Http.Features.Tests/project.json
index f3e96787e7..4ee107eb4e 100644
--- a/test/Microsoft.AspNetCore.Http.Features.Tests/project.json
+++ b/test/Microsoft.AspNetCore.Http.Features.Tests/project.json
@@ -16,7 +16,8 @@
     "dnxcore50": { 
       "dependencies": {
         "xunit.runner.aspnet": "2.0.0-aspnet-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   },
   "testRunner": "xunit",
diff --git a/test/Microsoft.AspNetCore.Http.Tests/project.json b/test/Microsoft.AspNetCore.Http.Tests/project.json
index de0767bedd..79b3bee8e3 100644
--- a/test/Microsoft.AspNetCore.Http.Tests/project.json
+++ b/test/Microsoft.AspNetCore.Http.Tests/project.json
@@ -16,7 +16,8 @@
     "dnxcore50": { 
       "dependencies": {
         "xunit.runner.aspnet": "2.0.0-aspnet-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   },
   "testRunner": "xunit",
diff --git a/test/Microsoft.AspNetCore.Owin.Tests/project.json b/test/Microsoft.AspNetCore.Owin.Tests/project.json
index 9a11ccaec8..c701ea94f7 100644
--- a/test/Microsoft.AspNetCore.Owin.Tests/project.json
+++ b/test/Microsoft.AspNetCore.Owin.Tests/project.json
@@ -18,7 +18,8 @@
     "dnxcore50": { 
       "dependencies": {
         "xunit.runner.aspnet": "2.0.0-aspnet-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   },
   "testRunner": "xunit",
diff --git a/test/Microsoft.AspNetCore.WebUtilities.Tests/project.json b/test/Microsoft.AspNetCore.WebUtilities.Tests/project.json
index 72e7a43c73..e6c1af340f 100644
--- a/test/Microsoft.AspNetCore.WebUtilities.Tests/project.json
+++ b/test/Microsoft.AspNetCore.WebUtilities.Tests/project.json
@@ -18,13 +18,14 @@
       },
       "dependencies": {
         "xunit.runner.console": "2.1.0"
-      }        
+      }
     },
     "dnxcore50": {
       "dependencies": {
         "System.Text.Encoding.Extensions": "4.0.11-*",
         "xunit.runner.aspnet": "2.0.0-aspnet-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   }
 }
diff --git a/test/Microsoft.Net.Http.Headers.Tests/project.json b/test/Microsoft.Net.Http.Headers.Tests/project.json
index 59cea6aca6..18b4161575 100644
--- a/test/Microsoft.Net.Http.Headers.Tests/project.json
+++ b/test/Microsoft.Net.Http.Headers.Tests/project.json
@@ -17,7 +17,8 @@
     "dnxcore50": { 
       "dependencies": {
         "xunit.runner.aspnet": "2.0.0-aspnet-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   },
   "testRunner": "xunit",