diff --git a/src/csharp/Grpc.Examples/project.json b/src/csharp/Grpc.Examples/project.json
index 21a730cb229d6e71b9e3aa65fbfc74db92c25aff..84254e897eddc53e2b5309b2aeeba3aec57ea0de 100644
--- a/src/csharp/Grpc.Examples/project.json
+++ b/src/csharp/Grpc.Examples/project.json
@@ -9,12 +9,7 @@
     "Google.Protobuf": "3.0.0"
   },
   "frameworks": {
-    "net45": {
-      "frameworkAssemblies": {
-        "System.Runtime": "",
-        "System.IO": ""
-      }
-    },
+    "net45": {},
     "netcoreapp1.0": {
       "dependencies": {
         "Microsoft.NETCore.App": {
diff --git a/src/csharp/Grpc.HealthCheck/project.json b/src/csharp/Grpc.HealthCheck/project.json
index 608d6454131ca6aedb4b1701731a59d117f61319..ce72395a9f99ab72509b592ea3c3e5f0ffd48f29 100644
--- a/src/csharp/Grpc.HealthCheck/project.json
+++ b/src/csharp/Grpc.HealthCheck/project.json
@@ -25,12 +25,7 @@
     "Google.Protobuf": "3.0.0"
   },
   "frameworks": {
-    "net45": {
-      "frameworkAssemblies": {
-        "System.Runtime": "",
-        "System.IO": ""
-      }
-    },
+    "net45": {},
     "netstandard1.5": {
       "dependencies": {
         "NETStandard.Library": "1.6.0"
diff --git a/src/csharp/Grpc.IntegrationTesting/project.json b/src/csharp/Grpc.IntegrationTesting/project.json
index e47b5953da0431595c3f91046d582a72ef60c64f..158ffd41b05e2e7841e3a0b5156bb9339fb8d140 100644
--- a/src/csharp/Grpc.IntegrationTesting/project.json
+++ b/src/csharp/Grpc.IntegrationTesting/project.json
@@ -62,10 +62,7 @@
   },
   "frameworks": {
     "net45": {
-      "frameworkAssemblies": {
-        "System.Runtime": "",
-        "System.IO": ""
-      }
+      "frameworkAssemblies": {}
     },
     "netcoreapp1.0": {
       "imports": [
diff --git a/src/csharp/Grpc.Reflection/project.json b/src/csharp/Grpc.Reflection/project.json
index bc4bca023afc4215ab7a6d1dcd4353a5cbca241a..f0897745633e7ea754b5848b8b95e94b36f34076 100644
--- a/src/csharp/Grpc.Reflection/project.json
+++ b/src/csharp/Grpc.Reflection/project.json
@@ -25,12 +25,7 @@
     "Google.Protobuf": "3.0.0"
   },
   "frameworks": {
-    "net45": {
-      "frameworkAssemblies": {
-        "System.Runtime": "",
-        "System.IO": ""
-      }
-    },
+    "net45": {},
     "netstandard1.5": {
       "dependencies": {
         "NETStandard.Library": "1.6.0"
diff --git a/templates/src/csharp/Grpc.Examples/project.json.template b/templates/src/csharp/Grpc.Examples/project.json.template
index b8a8314de177ab7376c669d02f970c476e78c9f2..42c2f31ce5c80016c718efffeeaece00ddbe5793 100644
--- a/templates/src/csharp/Grpc.Examples/project.json.template
+++ b/templates/src/csharp/Grpc.Examples/project.json.template
@@ -9,12 +9,7 @@
       "Google.Protobuf": "3.0.0"
     },
     "frameworks": {
-      "net45": {
-        "frameworkAssemblies": {
-          "System.Runtime": "",
-          "System.IO": ""
-        }
-      },
+      "net45": {},
       "netcoreapp1.0": {
         "dependencies": {
           "Microsoft.NETCore.App": {
diff --git a/templates/src/csharp/Grpc.HealthCheck/project.json.template b/templates/src/csharp/Grpc.HealthCheck/project.json.template
index cba68940153c16270f5bb02612c4e8db6fea0876..280d529e734fb92c01b024e06a1ad5e20954d99f 100644
--- a/templates/src/csharp/Grpc.HealthCheck/project.json.template
+++ b/templates/src/csharp/Grpc.HealthCheck/project.json.template
@@ -27,12 +27,7 @@
       "Google.Protobuf": "3.0.0"
     },
     "frameworks": {
-      "net45": {
-        "frameworkAssemblies": {
-          "System.Runtime": "",
-          "System.IO": ""
-        }
-      },
+      "net45": {},
       "netstandard1.5": {
         "dependencies": {
           "NETStandard.Library": "1.6.0"
diff --git a/templates/src/csharp/Grpc.IntegrationTesting/project.json.template b/templates/src/csharp/Grpc.IntegrationTesting/project.json.template
index 3ce94e58387db8ba8c0f1d58e889230a13b457de..4d54e63a0e5c40ea697d139a52203b782ef699e8 100644
--- a/templates/src/csharp/Grpc.IntegrationTesting/project.json.template
+++ b/templates/src/csharp/Grpc.IntegrationTesting/project.json.template
@@ -17,10 +17,7 @@
     },
     "frameworks": {
       "net45": {
-        "frameworkAssemblies": {
-          "System.Runtime": "",
-          "System.IO": ""
-        }
+        "frameworkAssemblies": {}
       },
       "netcoreapp1.0": {
         "imports": [
diff --git a/templates/src/csharp/Grpc.Reflection/project.json.template b/templates/src/csharp/Grpc.Reflection/project.json.template
index 8a33e1ccc97750b690052a1d05a375323c1ea87f..6d1c3e891f307c60062ed4167fb860d96fc4fd7f 100644
--- a/templates/src/csharp/Grpc.Reflection/project.json.template
+++ b/templates/src/csharp/Grpc.Reflection/project.json.template
@@ -27,12 +27,7 @@
       "Google.Protobuf": "3.0.0"
     },
     "frameworks": {
-      "net45": {
-        "frameworkAssemblies": {
-          "System.Runtime": "",
-          "System.IO": ""
-        }
-      },
+      "net45": {},
       "netstandard1.5": {
         "dependencies": {
           "NETStandard.Library": "1.6.0"