diff --git a/src/Microsoft.AspNetCore.Html.Abstractions/project.json b/src/Microsoft.AspNetCore.Html.Abstractions/project.json
index 55cc30d9b1..03334e45aa 100644
--- a/src/Microsoft.AspNetCore.Html.Abstractions/project.json
+++ b/src/Microsoft.AspNetCore.Html.Abstractions/project.json
@@ -10,7 +10,8 @@
     "keyFile": "../../tools/Key.snk"
   },
   "dependencies": {
-    "System.Text.Encodings.Web": "4.0.0-*"
+    "System.Text.Encodings.Web": "4.0.0-*",
+    "Microsoft.NETCore.Platforms": "1.0.1-*"
   },
   "frameworks": {
     "net451": {
@@ -23,7 +24,8 @@
       "dependencies": {
         "System.Collections": "4.0.11-*",
         "System.Resources.ResourceManager": "4.0.1-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   }
 }
diff --git a/src/Microsoft.Extensions.WebEncoders/project.json b/src/Microsoft.Extensions.WebEncoders/project.json
index 0facfeeb8c..f56cd3d4b6 100644
--- a/src/Microsoft.Extensions.WebEncoders/project.json
+++ b/src/Microsoft.Extensions.WebEncoders/project.json
@@ -13,6 +13,7 @@
   "dependencies": {
     "Microsoft.Extensions.DependencyInjection.Abstractions": "1.0.0-*",
     "Microsoft.Extensions.Options": "1.0.0-*",
+    "Microsoft.NETCore.Platforms": "1.0.1-*",
     "System.Text.Encodings.Web": "4.0.0-*"
   },
   "frameworks": {
@@ -22,6 +23,8 @@
         "System.Runtime": ""
       }
     },
-    "dotnet5.4": {}
+    "dotnet5.4": {
+      "imports": "portable-net451+win8"
+    }
   }
 }
diff --git a/test/Microsoft.AspNetCore.Html.Abstractions.Test/project.json b/test/Microsoft.AspNetCore.Html.Abstractions.Test/project.json
index d796493c0a..7e104bae8d 100644
--- a/test/Microsoft.AspNetCore.Html.Abstractions.Test/project.json
+++ b/test/Microsoft.AspNetCore.Html.Abstractions.Test/project.json
@@ -23,7 +23,8 @@
       "dependencies": {
         "System.Runtime": "4.0.21-*",
         "xunit.runner.aspnet": "2.0.0-aspnet-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   }
 }
diff --git a/test/Microsoft.Extensions.WebEncoders.Tests/project.json b/test/Microsoft.Extensions.WebEncoders.Tests/project.json
index c588c7a29e..ebfb18cf96 100644
--- a/test/Microsoft.Extensions.WebEncoders.Tests/project.json
+++ b/test/Microsoft.Extensions.WebEncoders.Tests/project.json
@@ -22,7 +22,8 @@
     "dnxcore50": { 
       "dependencies": {
         "xunit.runner.aspnet": "2.0.0-aspnet-*"
-      }
+      },
+      "imports": "portable-net451+win8"
     }
   }
 }