diff --git a/binding.gyp b/binding.gyp
index 6fbe59bd6e5..c521a27c300 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -43,7 +43,11 @@
     # out. It can be re-enabled for one build by setting the npm config
     # variable grpc_uv to true, and it can be re-enabled permanently by
     # setting it to true here.
-    'grpc_uv%': 'false'
+    'grpc_uv%': 'false',
+    # Some Node installations use the system installation of OpenSSL, and on
+    # some systems, the system OpenSSL still does not have ALPN support. This
+    # will let users recompile gRPC to work without ALPN.
+    'grpc_alpn%': 'true'
   },
   'target_defaults': {
     'include_dirs': [
@@ -73,10 +77,16 @@
           'OPENSSL_NO_ASM'
         ]
       }, {
-        # As of the beginning of 2017, we only support versions of Node with
-        # embedded versions of OpenSSL that support ALPN
-        'defines': [
-          'TSI_OPENSSL_ALPN_SUPPORT=1'
+        'conditions': [
+          ['grpc_alpn=="true"', {
+            'defines': [
+              'TSI_OPENSSL_ALPN_SUPPORT=1'
+            ],
+          }, {
+            'defines': [
+              'TSI_OPENSSL_ALPN_SUPPORT=0'
+            ],
+          }]
         ],
         'include_dirs': [
           '<(node_root_dir)/deps/openssl/openssl/include',
diff --git a/src/csharp/Grpc.Examples/project.json b/src/csharp/Grpc.Examples/project.json
index 21a730cb229..84254e897ed 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 5d3b2f554b1..db99b317e82 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 eba54318a5b..b86227a2589 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 bfc57661eb3..dfb9ba50213 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/src/ruby/ext/grpc/extconf.rb b/src/ruby/ext/grpc/extconf.rb
index b379664bab8..ecb66239b90 100644
--- a/src/ruby/ext/grpc/extconf.rb
+++ b/src/ruby/ext/grpc/extconf.rb
@@ -27,6 +27,7 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+require 'etc'
 require 'mkmf'
 
 LIBDIR = RbConfig::CONFIG['libdir']
@@ -80,7 +81,9 @@ ENV['BUILDDIR'] = output_dir
 
 unless windows
   puts 'Building internal gRPC into ' + grpc_lib_dir
-  system("make -j -C #{grpc_root} #{grpc_lib_dir}/libgrpc.a CONFIG=#{grpc_config}")
+  nproc = 4
+  nproc = Etc.nprocessors * 2 if Etc.respond_to? :nprocessors
+  system("make -j#{nproc} -C #{grpc_root} #{grpc_lib_dir}/libgrpc.a CONFIG=#{grpc_config}")
   exit 1 unless $? == 0
 end
 
diff --git a/templates/binding.gyp.template b/templates/binding.gyp.template
index 2290411d541..5e401e89773 100644
--- a/templates/binding.gyp.template
+++ b/templates/binding.gyp.template
@@ -45,7 +45,11 @@
       # out. It can be re-enabled for one build by setting the npm config
       # variable grpc_uv to true, and it can be re-enabled permanently by
       # setting it to true here.
-      'grpc_uv%': 'false'
+      'grpc_uv%': 'false',
+      # Some Node installations use the system installation of OpenSSL, and on
+      # some systems, the system OpenSSL still does not have ALPN support. This
+      # will let users recompile gRPC to work without ALPN.
+      'grpc_alpn%': 'true'
     },
     'target_defaults': {
       'include_dirs': [
@@ -75,10 +79,16 @@
             'OPENSSL_NO_ASM'
           ]
         }, {
-          # As of the beginning of 2017, we only support versions of Node with
-          # embedded versions of OpenSSL that support ALPN
-          'defines': [
-            'TSI_OPENSSL_ALPN_SUPPORT=1'
+          'conditions': [
+            ['grpc_alpn=="true"', {
+              'defines': [
+                'TSI_OPENSSL_ALPN_SUPPORT=1'
+              ],
+            }, {
+              'defines': [
+                'TSI_OPENSSL_ALPN_SUPPORT=0'
+              ],
+            }]
           ],
           'include_dirs': [
             '<(node_root_dir)/deps/openssl/openssl/include',
diff --git a/templates/src/csharp/Grpc.Examples/project.json.template b/templates/src/csharp/Grpc.Examples/project.json.template
index b8a8314de17..42c2f31ce5c 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 cba68940153..280d529e734 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 3ce94e58387..4d54e63a0e5 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 8a33e1ccc97..6d1c3e891f3 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"