diff --git a/src/Directory.Build.props b/src/Directory.Build.props
index e3e1feb526..a57bbf9638 100644
--- a/src/Directory.Build.props
+++ b/src/Directory.Build.props
@@ -60,4 +60,10 @@
     <PackageReference Include="SIL.ReleaseTasks" Version="2.5.0" PrivateAssets="All" Condition="'$(Configuration)' != 'Debug'" />
   </ItemGroup>
 
+  <!-- "Sentry" uses "Polyfill" and gives access to it's internals via "InternalsVisibleTo", but some Polyfills are in a separate namespace -->
+  <ItemGroup Condition="'$(MSBuildProjectName)' != 'Sentry' And $(MSBuildProjectName.StartsWith('Sentry.'))">
+    <!-- the latest TargetFramework requires no Polyfills; "Sentry.Compiler.Extensions" has its own Polyfills -->
+    <Using Include="Polyfills" Condition="'$(TargetFramework)' != $(LatestTfm) And $(MSBuildProjectName) != 'Sentry.Compiler.Extensions'" />
+  </ItemGroup>
+
 </Project>
diff --git a/src/Sentry.Analyzers/Sentry.Analyzers.csproj b/src/Sentry.Analyzers/Sentry.Analyzers.csproj
index 223a1434f8..e855f9d246 100644
--- a/src/Sentry.Analyzers/Sentry.Analyzers.csproj
+++ b/src/Sentry.Analyzers/Sentry.Analyzers.csproj
@@ -24,8 +24,18 @@
       https://github.com/SimonCropp/Polyfill
     -->
     <ItemGroup>
-      <PackageReference Include="Polyfill" Version="1.32.0" PrivateAssets="all" />
+      <PackageReference Include="Polyfill" Version="9.8.1" PrivateAssets="all" />
     </ItemGroup>
+    <Target Name="BeforePreparePolyfill" BeforeTargets="PreparePolyfill">
+      <PropertyGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
+        <PolyfillNoWarnIncorrectVersion>true</PolyfillNoWarnIncorrectVersion>
+      </PropertyGroup>
+    </Target>
+    <Target Name="AfterPreparePolyfill" AfterTargets="PreparePolyfill" DependsOnTargets="PreparePolyfill">
+      <PropertyGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
+        <DefineConstants>$([System.String]::Copy('$(DefineConstants)').Replace('FeatureMemory','').Replace(';;',';'))</DefineConstants>
+      </PropertyGroup>
+    </Target>
 
     <ItemGroup>
       <Using Remove="System.Text.Json" />
diff --git a/src/Sentry/Internal/Extensions/CollectionsExtensions.cs b/src/Sentry/Internal/Extensions/CollectionsExtensions.cs
index 8d7b6f7bdf..79a0fb4d44 100644
--- a/src/Sentry/Internal/Extensions/CollectionsExtensions.cs
+++ b/src/Sentry/Internal/Extensions/CollectionsExtensions.cs
@@ -69,18 +69,14 @@ public static IEnumerable<KeyValuePair<TKey, TValue>> WhereNotNullValue<TKey, TV
             }
         }
     }
+
     public static IEnumerable<KeyValuePair<TKey, TValue>> Append<TKey, TValue>(
         this IEnumerable<KeyValuePair<TKey, TValue>> source, TKey key, TValue value) =>
         source.Append(new KeyValuePair<TKey, TValue>(key, value));
+
     public static IReadOnlyList<T> AsReadOnly<T>(this IList<T> list) =>
         list as IReadOnlyList<T> ?? new ReadOnlyCollection<T>(list);
 
-#if !NET7_0_OR_GREATER
-    public static IReadOnlyDictionary<TKey, TValue> AsReadOnly<TKey, TValue>(this IDictionary<TKey, TValue> dictionary)
-        where TKey : notnull =>
-        new ReadOnlyDictionary<TKey, TValue>(dictionary);
-#endif
-
     public static IEnumerable<T> ExceptNulls<T>(this IEnumerable<T?> source) =>
         source.Where(x => x != null).Select(x => x!);
 
diff --git a/src/Sentry/Sentry.csproj b/src/Sentry/Sentry.csproj
index a2b75db0ae..f2f88ca2d5 100644
--- a/src/Sentry/Sentry.csproj
+++ b/src/Sentry/Sentry.csproj
@@ -65,8 +65,12 @@
     https://github.com/SimonCropp/Polyfill
   -->
   <ItemGroup>
-    <PackageReference Include="Polyfill" Version="1.32.0" PrivateAssets="all" />
+    <PackageReference Include="Polyfill" Version="9.8.1" PrivateAssets="all" />
   </ItemGroup>
+  <PropertyGroup>
+    <DefineConstants Condition="'$(TargetFramework)' == 'netstandard2.0'">$(DefineConstants);FeatureHttp</DefineConstants>
+    <DefineConstants Condition="'$(TargetFramework)' == 'netstandard2.1'">$(DefineConstants);FeatureHttp</DefineConstants>
+  </PropertyGroup>
 
   <!--
     On .NET Framework, we need a package reference to System.Runtime.InteropServices.RuntimeInformation.
diff --git a/test/Directory.Build.props b/test/Directory.Build.props
index 7559ec9d73..43c5f797ab 100644
--- a/test/Directory.Build.props
+++ b/test/Directory.Build.props
@@ -79,4 +79,10 @@
     <PackageReference Include="System.Text.RegularExpressions" Version="4.3.1" />
   </ItemGroup>
 
+  <!-- "Sentry" uses "Polyfill" and gives access to it's internals via "InternalsVisibleTo", but some Polyfills are in a separate namespace -->
+  <ItemGroup Condition="'$(MSBuildProjectName)' != 'Sentry' And $(MSBuildProjectName.StartsWith('Sentry.'))">
+    <!-- the latest TargetFramework requires no Polyfills -->
+    <Using Include="Polyfills" Condition="'$(TargetFramework)' != $(LatestTfm)" />
+  </ItemGroup>
+
 </Project>