diff --git a/src/Orchard.Web/Modules/Orchard.Glimpse/Orchard.Glimpse.csproj b/src/Orchard.Web/Modules/Orchard.Glimpse/Orchard.Glimpse.csproj
index 3352e7942..67bd217c3 100644
--- a/src/Orchard.Web/Modules/Orchard.Glimpse/Orchard.Glimpse.csproj
+++ b/src/Orchard.Web/Modules/Orchard.Glimpse/Orchard.Glimpse.csproj
@@ -36,6 +36,7 @@
     <WarningLevel>4</WarningLevel>
     <CodeAnalysisRuleSet>..\..\..\OrchardBasicCorrectness.ruleset</CodeAnalysisRuleSet>
     <Prefer32Bit>false</Prefer32Bit>
+    <LangVersion>5</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -46,6 +47,7 @@
     <WarningLevel>4</WarningLevel>
     <CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
     <Prefer32Bit>false</Prefer32Bit>
+    <LangVersion>5</LangVersion>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="Autofac, Version=3.5.0.0, Culture=neutral, PublicKeyToken=17863af14b0044da, processorArchitecture=MSIL">
diff --git a/src/Orchard.Web/Modules/Orchard.OpenId/Orchard.OpenId.csproj b/src/Orchard.Web/Modules/Orchard.OpenId/Orchard.OpenId.csproj
index 7971ec25e..0ee4a0611 100644
--- a/src/Orchard.Web/Modules/Orchard.OpenId/Orchard.OpenId.csproj
+++ b/src/Orchard.Web/Modules/Orchard.OpenId/Orchard.OpenId.csproj
@@ -36,6 +36,7 @@
     <WarningLevel>4</WarningLevel>
     <CodeAnalysisRuleSet>..\..\..\OrchardBasicCorrectness.ruleset</CodeAnalysisRuleSet>
     <Prefer32Bit>false</Prefer32Bit>
+    <LangVersion>5</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -46,6 +47,7 @@
     <WarningLevel>4</WarningLevel>
     <CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
     <Prefer32Bit>false</Prefer32Bit>
+    <LangVersion>5</LangVersion>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="Iesi.Collections, Version=4.0.0.0, Culture=neutral, PublicKeyToken=aa95f207798dfdb4, processorArchitecture=MSIL">