diff --git a/src/Verify.ExceptionParsing/Verify.ExceptionParsing.csproj b/src/Verify.ExceptionParsing/Verify.ExceptionParsing.csproj
index 208eaa60d5..b3e0a744a4 100644
--- a/src/Verify.ExceptionParsing/Verify.ExceptionParsing.csproj
+++ b/src/Verify.ExceptionParsing/Verify.ExceptionParsing.csproj
@@ -3,7 +3,7 @@
     <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Polyfill" Version="3.0.0" PrivateAssets="all" />
+    <PackageReference Include="Polyfill" Version="4.0.0" PrivateAssets="all" />
     <PackageReference Include="ProjectDefaults" Version="1.0.125" PrivateAssets="all" />
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/src/Verify.Fixie/Verify.Fixie.csproj b/src/Verify.Fixie/Verify.Fixie.csproj
index e5ce1f44aa..a9999f6c63 100644
--- a/src/Verify.Fixie/Verify.Fixie.csproj
+++ b/src/Verify.Fixie/Verify.Fixie.csproj
@@ -9,7 +9,7 @@
     <PackageReference Include="Fixie" Version="3.4.0" />
     <PackageReference Include="ProjectDefaults" Version="1.0.125" PrivateAssets="all" />
     <PackageReference Include="EmptyFiles" Version="8.2.0" PrivateAssets="None" />
-    <PackageReference Include="Polyfill" Version="3.0.0" PrivateAssets="all" />
+    <PackageReference Include="Polyfill" Version="4.0.0" PrivateAssets="all" />
     <ProjectReference Include="..\Verify\Verify.csproj" PrivateAssets="None" />
     <None Include="buildTransitive\Verify.Fixie.props" Pack="true" PackagePath="buildTransitive\Verify.Fixie.props" />
     <None Include="buildTransitive\Verify.Fixie.props" Pack="true" PackagePath="build\Verify.Fixie.props" />
diff --git a/src/Verify/Verify.csproj b/src/Verify/Verify.csproj
index e0ca894e53..39baba08b1 100644
--- a/src/Verify/Verify.csproj
+++ b/src/Verify/Verify.csproj
@@ -8,7 +8,7 @@
     <DefineConstants>$(DefineConstants);DiffEngine</DefineConstants>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Polyfill" Version="3.0.0" PrivateAssets="all" />
+    <PackageReference Include="Polyfill" Version="4.0.0" PrivateAssets="all" />
     <PackageReference Include="System.IO.Compression" Version="4.3.0" Condition="$(TargetFrameworkIdentifier) == '.NETFramework'" />
     <PackageReference Include="System.IO.Hashing" Version="8.0.0" Condition="$(TargetFrameworkIdentifier) == '.NETFramework' or $(TargetFramework) == 'net6.0' or $(TargetFramework) == 'net7.0' or $(TargetFramework) == 'net8.0' or $(TargetFramework) == 'net9.0'" />
     <PackageReference Include="System.Memory" Version="4.5.5" Condition="$(TargetFrameworkIdentifier) == '.NETFramework'" />