diff --git a/PropertyChangedAnalyzers.Test/PropertyChangedAnalyzers.Test.csproj b/PropertyChangedAnalyzers.Test/PropertyChangedAnalyzers.Test.csproj
index 2363070d..6a29995d 100644
--- a/PropertyChangedAnalyzers.Test/PropertyChangedAnalyzers.Test.csproj
+++ b/PropertyChangedAnalyzers.Test/PropertyChangedAnalyzers.Test.csproj
@@ -23,7 +23,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Caliburn.Micro" Version="3.2" />
+    <PackageReference Include="Caliburn.Micro" Version="4.0.173" />
     <PackageReference Include="Gu.Analyzers" Version="2.0.2" PrivateAssets="all" />
     <PackageReference Include="Gu.Roslyn.Asserts" Version="4.3.0" />
     <PackageReference Include="Gu.Roslyn.Asserts.Analyzers" Version="4.0.0" PrivateAssets="all" />
diff --git a/ValidCode/ValidCode.csproj b/ValidCode/ValidCode.csproj
index 54916722..e222f88d 100644
--- a/ValidCode/ValidCode.csproj
+++ b/ValidCode/ValidCode.csproj
@@ -9,7 +9,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Caliburn.Micro" Version="3.2" />
+    <PackageReference Include="Caliburn.Micro" Version="4.0.173" />
     <PackageReference Include="Gu.Wpf.Reactive" Version="5.0.1" />
     <PackageReference Include="MvvmCross" Version="8.0.2" />
     <PackageReference Include="MvvmLightLibs" Version="5.4.1.1" />