diff --git a/src/CredentialManagement/CredentialManagement.csproj b/src/CredentialManagement/CredentialManagement.csproj
index f1f0d4d672..92ec3fb612 100644
--- a/src/CredentialManagement/CredentialManagement.csproj
+++ b/src/CredentialManagement/CredentialManagement.csproj
@@ -9,6 +9,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>CredentialManagement</RootNamespace>
     <AssemblyName>GitHub.CredentialManagement</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>
diff --git a/src/GitHub.Api/GitHub.Api.csproj b/src/GitHub.Api/GitHub.Api.csproj
index fc35dd136b..58f63e5ef0 100644
--- a/src/GitHub.Api/GitHub.Api.csproj
+++ b/src/GitHub.Api/GitHub.Api.csproj
@@ -9,6 +9,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub.Api</RootNamespace>
     <AssemblyName>GitHub.Api</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>
diff --git a/src/GitHub.App/GitHub.App.csproj b/src/GitHub.App/GitHub.App.csproj
index 5a305566ea..9011acecaf 100644
--- a/src/GitHub.App/GitHub.App.csproj
+++ b/src/GitHub.App/GitHub.App.csproj
@@ -11,6 +11,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub.App</RootNamespace>
     <AssemblyName>GitHub.App</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>
diff --git a/src/GitHub.Exports.Reactive/GitHub.Exports.Reactive.csproj b/src/GitHub.Exports.Reactive/GitHub.Exports.Reactive.csproj
index 0da06b8315..a55d6aa910 100644
--- a/src/GitHub.Exports.Reactive/GitHub.Exports.Reactive.csproj
+++ b/src/GitHub.Exports.Reactive/GitHub.Exports.Reactive.csproj
@@ -10,6 +10,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub</RootNamespace>
     <AssemblyName>GitHub.Exports.Reactive</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>
diff --git a/src/GitHub.Exports/GitHub.Exports.csproj b/src/GitHub.Exports/GitHub.Exports.csproj
index 6f9a3a3d1f..417643cbeb 100644
--- a/src/GitHub.Exports/GitHub.Exports.csproj
+++ b/src/GitHub.Exports/GitHub.Exports.csproj
@@ -10,6 +10,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub</RootNamespace>
     <AssemblyName>GitHub.Exports</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>
diff --git a/src/GitHub.Extensions.Reactive/GitHub.Extensions.Reactive.csproj b/src/GitHub.Extensions.Reactive/GitHub.Extensions.Reactive.csproj
index 7e99b64e6c..689d4764a1 100644
--- a/src/GitHub.Extensions.Reactive/GitHub.Extensions.Reactive.csproj
+++ b/src/GitHub.Extensions.Reactive/GitHub.Extensions.Reactive.csproj
@@ -9,6 +9,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub.Extensions.Reactive</RootNamespace>
     <AssemblyName>GitHub.Extensions.Reactive</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>
diff --git a/src/GitHub.Extensions/GitHub.Extensions.csproj b/src/GitHub.Extensions/GitHub.Extensions.csproj
index ca025c083d..cbdbd00373 100644
--- a/src/GitHub.Extensions/GitHub.Extensions.csproj
+++ b/src/GitHub.Extensions/GitHub.Extensions.csproj
@@ -9,6 +9,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub.Extensions</RootNamespace>
     <AssemblyName>GitHub.Extensions</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>
diff --git a/src/GitHub.InlineReviews/GitHub.InlineReviews.csproj b/src/GitHub.InlineReviews/GitHub.InlineReviews.csproj
index ec6a0f63d9..5f35f609f4 100644
--- a/src/GitHub.InlineReviews/GitHub.InlineReviews.csproj
+++ b/src/GitHub.InlineReviews/GitHub.InlineReviews.csproj
@@ -22,6 +22,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub.InlineReviews</RootNamespace>
     <AssemblyName>GitHub.InlineReviews</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <GeneratePkgDefFile>true</GeneratePkgDefFile>
     <IncludeAssemblyInVSIXContainer>true</IncludeAssemblyInVSIXContainer>
diff --git a/src/GitHub.Logging/GitHub.Logging.csproj b/src/GitHub.Logging/GitHub.Logging.csproj
index c55aa30653..3a000a695f 100644
--- a/src/GitHub.Logging/GitHub.Logging.csproj
+++ b/src/GitHub.Logging/GitHub.Logging.csproj
@@ -9,6 +9,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub</RootNamespace>
     <AssemblyName>GitHub.Logging</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <TargetFrameworkProfile />
diff --git a/src/GitHub.Services.Vssdk/GitHub.Services.Vssdk.csproj b/src/GitHub.Services.Vssdk/GitHub.Services.Vssdk.csproj
index 1bd5ab4904..58353ed1a9 100644
--- a/src/GitHub.Services.Vssdk/GitHub.Services.Vssdk.csproj
+++ b/src/GitHub.Services.Vssdk/GitHub.Services.Vssdk.csproj
@@ -9,6 +9,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub.Services.Vssdk</RootNamespace>
     <AssemblyName>GitHub.Services.Vssdk</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>
diff --git a/src/GitHub.StartPage/GitHub.StartPage.csproj b/src/GitHub.StartPage/GitHub.StartPage.csproj
index f5be5ec548..3978c1c331 100644
--- a/src/GitHub.StartPage/GitHub.StartPage.csproj
+++ b/src/GitHub.StartPage/GitHub.StartPage.csproj
@@ -20,6 +20,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub.StartPage</RootNamespace>
     <AssemblyName>GitHub.StartPage</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <GeneratePkgDefFile>true</GeneratePkgDefFile>
     <IncludeAssemblyInVSIXContainer>true</IncludeAssemblyInVSIXContainer>
diff --git a/src/GitHub.TeamFoundation.14/GitHub.TeamFoundation.14.csproj b/src/GitHub.TeamFoundation.14/GitHub.TeamFoundation.14.csproj
index 20bfe2c1d4..2e286bb280 100644
--- a/src/GitHub.TeamFoundation.14/GitHub.TeamFoundation.14.csproj
+++ b/src/GitHub.TeamFoundation.14/GitHub.TeamFoundation.14.csproj
@@ -12,6 +12,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub.TeamFoundation</RootNamespace>
     <AssemblyName>GitHub.TeamFoundation.14</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>
diff --git a/src/GitHub.TeamFoundation.15/GitHub.TeamFoundation.15.csproj b/src/GitHub.TeamFoundation.15/GitHub.TeamFoundation.15.csproj
index 4df741a907..a91b03e9e6 100644
--- a/src/GitHub.TeamFoundation.15/GitHub.TeamFoundation.15.csproj
+++ b/src/GitHub.TeamFoundation.15/GitHub.TeamFoundation.15.csproj
@@ -12,6 +12,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub.TeamFoundation</RootNamespace>
     <AssemblyName>GitHub.TeamFoundation.15</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>
diff --git a/src/GitHub.UI.Reactive/GitHub.UI.Reactive.csproj b/src/GitHub.UI.Reactive/GitHub.UI.Reactive.csproj
index 044c05fc1f..ceaeb05973 100644
--- a/src/GitHub.UI.Reactive/GitHub.UI.Reactive.csproj
+++ b/src/GitHub.UI.Reactive/GitHub.UI.Reactive.csproj
@@ -10,6 +10,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub</RootNamespace>
     <AssemblyName>GitHub.UI.Reactive</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>
diff --git a/src/GitHub.UI/GitHub.UI.csproj b/src/GitHub.UI/GitHub.UI.csproj
index ae7d07f227..916d1cb412 100644
--- a/src/GitHub.UI/GitHub.UI.csproj
+++ b/src/GitHub.UI/GitHub.UI.csproj
@@ -10,6 +10,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub.UI</RootNamespace>
     <AssemblyName>GitHub.UI</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>
diff --git a/src/GitHub.VisualStudio.UI/GitHub.VisualStudio.UI.csproj b/src/GitHub.VisualStudio.UI/GitHub.VisualStudio.UI.csproj
index c6b964af59..12dcbc5178 100644
--- a/src/GitHub.VisualStudio.UI/GitHub.VisualStudio.UI.csproj
+++ b/src/GitHub.VisualStudio.UI/GitHub.VisualStudio.UI.csproj
@@ -9,6 +9,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>GitHub.VisualStudio.UI</RootNamespace>
     <AssemblyName>GitHub.VisualStudio.UI</AssemblyName>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>
diff --git a/src/GitHub.VisualStudio/GitHub.VisualStudio.csproj b/src/GitHub.VisualStudio/GitHub.VisualStudio.csproj
index a985af82ba..aa7ba8635f 100644
--- a/src/GitHub.VisualStudio/GitHub.VisualStudio.csproj
+++ b/src/GitHub.VisualStudio/GitHub.VisualStudio.csproj
@@ -29,6 +29,7 @@
     <StartAction>Program</StartAction>
     <StartProgram>$(DevEnvDir)\devenv.exe</StartProgram>
     <StartArguments>/rootsuffix Exp</StartArguments>
+    <LangVersion>6</LangVersion>
     <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <ZipPackageCompressionLevel>Normal</ZipPackageCompressionLevel>
     <CodeAnalysisRuleSet>..\common\GitHubVS.ruleset</CodeAnalysisRuleSet>