diff --git a/tools/Microsoft.AspNet.Server.Kestrel.GeneratedCode/project.json b/tools/Microsoft.AspNet.Server.Kestrel.GeneratedCode/project.json
index bfcbc212b3..6bede83d5a 100644
--- a/tools/Microsoft.AspNet.Server.Kestrel.GeneratedCode/project.json
+++ b/tools/Microsoft.AspNet.Server.Kestrel.GeneratedCode/project.json
@@ -12,9 +12,9 @@
     "frameworks": {
         "dnx451": {
             "frameworkAssemblies": {
-                "System.Runtime": "4.0.10.0",
-                "System.Text.Encoding": "4.0.0.0",
-                "System.Threading.Tasks": "4.0.0.0"
+                "System.Runtime": "",
+                "System.Text.Encoding": "",
+                "System.Threading.Tasks": ""
             }
         }
     }