diff --git a/src/Microsoft.AspNet.FeatureModel/project.json b/src/Microsoft.AspNet.FeatureModel/project.json
index 1c37fbed40..595978bef8 100644
--- a/src/Microsoft.AspNet.FeatureModel/project.json
+++ b/src/Microsoft.AspNet.FeatureModel/project.json
@@ -5,13 +5,13 @@
     "aspnet50": {},
     "aspnetcore50": {
       "dependencies": {
-        "System.Collections": "4.0.10.0",
-        "System.Linq": "4.0.0.0",
-        "System.Reflection": "4.0.10.0",
-        "System.Reflection.TypeExtensions": "4.0.0.0",
-        "System.Runtime": "4.0.20.0",
-        "System.Runtime.InteropServices": "4.0.20.0",
-        "System.Threading": "4.0.0.0"
+        "System.Collections": "4.0.10-beta-*",
+        "System.Linq": "4.0.0-beta-*",
+        "System.Reflection": "4.0.10-beta-*",
+        "System.Reflection.TypeExtensions": "4.0.0-beta-*",
+        "System.Runtime": "4.0.20-beta-*",
+        "System.Runtime.InteropServices": "4.0.20-beta-*",
+        "System.Threading": "4.0.0-beta-*"
       }
     }
   }
diff --git a/src/Microsoft.AspNet.Http.Extensions/project.json b/src/Microsoft.AspNet.Http.Extensions/project.json
index b19b3871c4..e4d49e2085 100644
--- a/src/Microsoft.AspNet.Http.Extensions/project.json
+++ b/src/Microsoft.AspNet.Http.Extensions/project.json
@@ -8,7 +8,7 @@
         },
         "aspnetcore50" : { 
             "dependencies": {
-                "System.Runtime": "4.0.20.0"
+                "System.Runtime": "4.0.20-beta-*"
             }
         }
     }
diff --git a/src/Microsoft.AspNet.Http/project.json b/src/Microsoft.AspNet.Http/project.json
index 4e4141ca40..fa763b1edb 100644
--- a/src/Microsoft.AspNet.Http/project.json
+++ b/src/Microsoft.AspNet.Http/project.json
@@ -6,19 +6,19 @@
     "aspnetcore50": {
       "dependencies": {
         "Microsoft.Net.WebSocketAbstractions": "1.0.0-*",
-        "System.Collections": "4.0.10.0",
-        "System.ComponentModel": "4.0.0.0",
-        "System.Diagnostics.Tools": "4.0.0.0",
-        "System.Globalization": "4.0.10.0",
-        "System.Globalization.Extensions": "4.0.0.0",
-        "System.IO": "4.0.10.0",
-        "System.Linq": "4.0.0.0",
-        "System.Runtime": "4.0.20.0",
-        "System.Runtime.Extensions": "4.0.10.0",
-        "System.Runtime.InteropServices": "4.0.20.0",
+        "System.Collections": "4.0.10-beta-*",
+        "System.ComponentModel": "4.0.0-beta-*",
+        "System.Diagnostics.Tools": "4.0.0-beta-*",
+        "System.Globalization": "4.0.10-beta-*",
+        "System.Globalization.Extensions": "4.0.0-beta-*",
+        "System.IO": "4.0.10-beta-*",
+        "System.Linq": "4.0.0-beta-*",
+        "System.Runtime": "4.0.20-beta-*",
+        "System.Runtime.Extensions": "4.0.10-beta-*",
+        "System.Runtime.InteropServices": "4.0.20-beta-*",
         "System.Security.Claims": "1.0.0-*",
-        "System.Security.Principal" : "4.0.0.0",
-        "System.Threading.Tasks": "4.0.10.0"
+        "System.Security.Principal" : "4.0.0-beta-*",
+        "System.Threading.Tasks": "4.0.10-beta-*"
       }
     }
   }
diff --git a/src/Microsoft.AspNet.HttpFeature/project.json b/src/Microsoft.AspNet.HttpFeature/project.json
index 0c685167ae..2706610f3e 100644
--- a/src/Microsoft.AspNet.HttpFeature/project.json
+++ b/src/Microsoft.AspNet.HttpFeature/project.json
@@ -5,14 +5,14 @@
     "aspnetcore50": {
       "dependencies": {
         "Microsoft.Net.WebSocketAbstractions": "1.0.0-*",
-        "System.IO": "4.0.10.0",
-        "System.Net.Primitives": "4.0.10.0",
-        "System.Runtime": "4.0.20.0",
-        "System.Runtime.InteropServices": "4.0.20.0",
+        "System.IO": "4.0.10-beta-*",
+        "System.Net.Primitives": "4.0.10-beta-*",
+        "System.Runtime": "4.0.20-beta-*",
+        "System.Runtime.InteropServices": "4.0.20-beta-*",
         "System.Security.Claims": "1.0.0-*",
-        "System.Security.Cryptography.X509Certificates": "4.0.0.0",
-        "System.Security.Principal": "4.0.0.0",
-        "System.Threading.Tasks": "4.0.10.0"
+        "System.Security.Cryptography.X509Certificates": "4.0.0-beta-*",
+        "System.Security.Principal": "4.0.0-beta-*",
+        "System.Threading.Tasks": "4.0.10-beta-*"
       }
     }
   }
diff --git a/src/Microsoft.AspNet.Owin/project.json b/src/Microsoft.AspNet.Owin/project.json
index 4bd0555d65..d1104b22ac 100644
--- a/src/Microsoft.AspNet.Owin/project.json
+++ b/src/Microsoft.AspNet.Owin/project.json
@@ -10,20 +10,20 @@
         "aspnet50": { },
         "aspnetcore50": {
             "dependencies": {
-                "System.Collections": "4.0.10.0",
-                "System.ComponentModel": "4.0.0.0",
-                "System.Diagnostics.Tools": "4.0.0.0",
-                "System.Globalization": "4.0.10.0",
-                "System.IO": "4.0.10.0",
-                "System.Linq": "4.0.0.0",
-                "System.Net.Primitives": "4.0.10.0",
-                "System.Runtime": "4.0.20.0",
-                "System.Runtime.Extensions": "4.0.10.0",
-                "System.Runtime.InteropServices": "4.0.20.0",
+                "System.Collections": "4.0.10-beta-*",
+                "System.ComponentModel": "4.0.0-beta-*",
+                "System.Diagnostics.Tools": "4.0.0-beta-*",
+                "System.Globalization": "4.0.10-beta-*",
+                "System.IO": "4.0.10-beta-*",
+                "System.Linq": "4.0.0-beta-*",
+                "System.Net.Primitives": "4.0.10-beta-*",
+                "System.Runtime": "4.0.20-beta-*",
+                "System.Runtime.Extensions": "4.0.10-beta-*",
+                "System.Runtime.InteropServices": "4.0.20-beta-*",
                 "System.Security.Claims": "1.0.0-*",
-                "System.Security.Cryptography.X509Certificates": "4.0.0.0",
-                "System.Security.Principal": "4.0.0.0",
-                "System.Threading.Tasks": "4.0.10.0"
+                "System.Security.Cryptography.X509Certificates": "4.0.0-beta-*",
+                "System.Security.Principal": "4.0.0-beta-*",
+                "System.Threading.Tasks": "4.0.10-beta-*"
             }
         }
     }
diff --git a/src/Microsoft.AspNet.PipelineCore/project.json b/src/Microsoft.AspNet.PipelineCore/project.json
index 41392e7cec..a2b0abf71f 100644
--- a/src/Microsoft.AspNet.PipelineCore/project.json
+++ b/src/Microsoft.AspNet.PipelineCore/project.json
@@ -12,20 +12,20 @@
     "aspnetcore50": {
       "dependencies": {
         "Microsoft.Net.WebSocketAbstractions": "1.0.0-*",
-        "System.Collections": "4.0.10.0",
-        "System.ComponentModel": "4.0.0.0",
-        "System.Diagnostics.Debug": "4.0.10.0",
-        "System.Diagnostics.Tools": "4.0.0.0",
-        "System.Globalization": "4.0.10.0",
-        "System.IO": "4.0.10.0",
-        "System.Linq": "4.0.0.0",
-        "System.Runtime": "4.0.20.0",
-        "System.Runtime.Extensions": "4.0.10.0",
-        "System.Runtime.InteropServices": "4.0.20.0",
+        "System.Collections": "4.0.10-beta-*",
+        "System.ComponentModel": "4.0.0-beta-*",
+        "System.Diagnostics.Debug": "4.0.10-beta-*",
+        "System.Diagnostics.Tools": "4.0.0-beta-*",
+        "System.Globalization": "4.0.10-beta-*",
+        "System.IO": "4.0.10-beta-*",
+        "System.Linq": "4.0.0-beta-*",
+        "System.Runtime": "4.0.20-beta-*",
+        "System.Runtime.Extensions": "4.0.10-beta-*",
+        "System.Runtime.InteropServices": "4.0.20-beta-*",
         "System.Security.Claims": "1.0.0-*",
-        "System.Security.Principal" : "4.0.0.0",
-        "System.Text.Encoding": "4.0.10.0",
-        "System.Threading.Tasks": "4.0.10.0"
+        "System.Security.Principal" : "4.0.0-beta-*",
+        "System.Text.Encoding": "4.0.10-beta-*",
+        "System.Threading.Tasks": "4.0.10-beta-*"
       }
     }
   }
diff --git a/src/Microsoft.AspNet.WebUtilities/project.json b/src/Microsoft.AspNet.WebUtilities/project.json
index e4f394f360..fcb9fea61d 100644
--- a/src/Microsoft.AspNet.WebUtilities/project.json
+++ b/src/Microsoft.AspNet.WebUtilities/project.json
@@ -7,7 +7,7 @@
     "aspnet50": {},
     "aspnetcore50": {
       "dependencies": {
-        "System.Runtime": "4.0.20.0"
+        "System.Runtime": "4.0.20-beta-*"
       }
     }
   }
diff --git a/test/Microsoft.AspNet.PipelineCore.Tests/project.json b/test/Microsoft.AspNet.PipelineCore.Tests/project.json
index 3eb49d4bed..a175d93546 100644
--- a/test/Microsoft.AspNet.PipelineCore.Tests/project.json
+++ b/test/Microsoft.AspNet.PipelineCore.Tests/project.json
@@ -15,7 +15,7 @@
                 "Moq": "4.2.1312.1622"
             },
             "frameworkAssemblies": {
-                "System.Net.Http": "4.0.0.0"
+                "System.Net.Http": "4.0.0-beta-*"
             }
         }
     }