diff --git a/Sources/BowlingApi/BowlingApi.csproj b/Sources/BowlingApi/BowlingApi.csproj
index 2b76c0b..7f0352f 100644
--- a/Sources/BowlingApi/BowlingApi.csproj
+++ b/Sources/BowlingApi/BowlingApi.csproj
@@ -4,7 +4,7 @@
         <TargetFramework>net6.0</TargetFramework>
         <Nullable>enable</Nullable>
         <ImplicitUsings>enable</ImplicitUsings>
-        <LangVersion>11</LangVersion>
+        <LangVersion>10</LangVersion>
     </PropertyGroup>
 
     <PropertyGroup Condition=" '$(RunConfiguration)' == 'https' " />
diff --git a/Sources/BowlingService/BowlingService.csproj b/Sources/BowlingService/BowlingService.csproj
index 5f4b6b5..0c30682 100644
--- a/Sources/BowlingService/BowlingService.csproj
+++ b/Sources/BowlingService/BowlingService.csproj
@@ -4,7 +4,7 @@
     <TargetFramework>net6.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
-    <LangVersion>11</LangVersion>
+    <LangVersion>10</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>