diff --git a/CHANGELOG.md b/CHANGELOG.md
index bf6c7fc..065469d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+0.5.1
+------
+
+- Downgrade required version of `Microsoft.CodeAnalysis.CSharp`.
+
 0.5.0
 ------
 
diff --git a/src/Dusharp.Package/Dusharp.Package.csproj b/src/Dusharp.Package/Dusharp.Package.csproj
index 5d87464..0bdfaa8 100644
--- a/src/Dusharp.Package/Dusharp.Package.csproj
+++ b/src/Dusharp.Package/Dusharp.Package.csproj
@@ -4,7 +4,7 @@
 		<TargetFramework>netstandard2.0</TargetFramework>
 		<EnforceExtendedAnalyzerRules>true</EnforceExtendedAnalyzerRules>
 		<SuppressDependenciesWhenPacking>true</SuppressDependenciesWhenPacking>
-		<Version>0.5.0</Version>
+		<Version>0.5.1</Version>
 		<Authors>Vitali Kolebyanov</Authors>
 		<Description>Dusharp is a C# source generator for creating discriminated unions.</Description>
 		<RepositoryUrl>https://github.com/kolebynov/Dusharp</RepositoryUrl>
diff --git a/src/Dusharp.SourceGenerator/Dusharp.SourceGenerator.csproj b/src/Dusharp.SourceGenerator/Dusharp.SourceGenerator.csproj
index c397638..ca8279a 100644
--- a/src/Dusharp.SourceGenerator/Dusharp.SourceGenerator.csproj
+++ b/src/Dusharp.SourceGenerator/Dusharp.SourceGenerator.csproj
@@ -9,7 +9,7 @@
 
 	<ItemGroup>
 		<PackageReference Include="Dusharp" Version="0.4.0" PrivateAssets="all"/>
-		<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.11.0"/>
+		<PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.3.1" />
 		<PackageReference Include="PolySharp" Version="1.14.1">
 			<PrivateAssets>all</PrivateAssets>
 			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>