diff --git a/X10D.Tests/X10D.Tests.csproj b/X10D.Tests/X10D.Tests.csproj
index 0ce043e..684b34a 100644
--- a/X10D.Tests/X10D.Tests.csproj
+++ b/X10D.Tests/X10D.Tests.csproj
@@ -4,6 +4,7 @@
         <TargetFramework>netcoreapp3.1</TargetFramework>
         <IsPackable>false</IsPackable>
         <CodeAnalysisRuleSet>..\X10D.ruleset</CodeAnalysisRuleSet>
+        <CodeAnalysisTreatWarningsAsErrors>true</CodeAnalysisTreatWarningsAsErrors>
     </PropertyGroup>
 
     <ItemGroup>
diff --git a/X10D/X10D.csproj b/X10D/X10D.csproj
index be004f5..63da2c5 100644
--- a/X10D/X10D.csproj
+++ b/X10D/X10D.csproj
@@ -15,6 +15,7 @@
         <PackageTags>dotnet extension-methods</PackageTags>
         <Version>2.1.1-alpha</Version>
         <CodeAnalysisRuleSet>..\X10D.ruleset</CodeAnalysisRuleSet>
+        <CodeAnalysisTreatWarningsAsErrors>true</CodeAnalysisTreatWarningsAsErrors>
     </PropertyGroup>
 
     <ItemGroup>