diff --git a/Tests/Benchmarks/Benchmarks.csproj b/Tests/Benchmarks/Benchmarks.csproj
index 302951fc31..a8936ebd3e 100644
--- a/Tests/Benchmarks/Benchmarks.csproj
+++ b/Tests/Benchmarks/Benchmarks.csproj
@@ -12,7 +12,7 @@
     <PackageReference Include="BenchmarkDotNet" Version="0.14.0" />
     <PackageReference Include="Bogus" Version="35.6.1" />
     <!-- Resolve MSB3277 -->
-    <PackageReference Include="System.Reflection.Metadata" Version="8.0.0" Condition="'$(TargetFramework)' == 'net472'" />
+    <PackageReference Include="System.Reflection.Metadata" Version="9.0.0" Condition="'$(TargetFramework)' == 'net472'" />
   </ItemGroup>
   <ItemGroup>
     <Reference Include="System.Net.Http" Condition="'$(TargetFramework)' == 'net472'" />
diff --git a/Tests/FluentAssertions.Equivalency.Specs/FluentAssertions.Equivalency.Specs.csproj b/Tests/FluentAssertions.Equivalency.Specs/FluentAssertions.Equivalency.Specs.csproj
index c1d4217282..bbeba7f560 100644
--- a/Tests/FluentAssertions.Equivalency.Specs/FluentAssertions.Equivalency.Specs.csproj
+++ b/Tests/FluentAssertions.Equivalency.Specs/FluentAssertions.Equivalency.Specs.csproj
@@ -17,7 +17,7 @@
       FluentAssertions.Specs.csproj for net47 does not generate a binding redirect from 4.0.4.0 to 4.0.4.1
       Upgrading to 1.6.0 gives "Could not load file or assembly 'System.Runtime.CompilerServices.Unsafe, Version=4.0.4.0"
     -->
-    <PackageReference Include="System.Collections.Immutable" Version="[1.5.0]" />
+    <PackageReference Include="System.Collections.Immutable" Version="[9.0.0]" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net6.0' OR '$(TargetFramework)' == 'net8.0'">
diff --git a/Tests/FluentAssertions.Specs/FluentAssertions.Specs.csproj b/Tests/FluentAssertions.Specs/FluentAssertions.Specs.csproj
index 3be852702e..7b86481f4d 100644
--- a/Tests/FluentAssertions.Specs/FluentAssertions.Specs.csproj
+++ b/Tests/FluentAssertions.Specs/FluentAssertions.Specs.csproj
@@ -17,7 +17,7 @@
       FluentAssertions.Specs.csproj for net47 does not generate a binding redirect from 4.0.4.0 to 4.0.4.1
       Upgrading to 1.6.0 gives "Could not load file or assembly 'System.Runtime.CompilerServices.Unsafe, Version=4.0.4.0"
     -->
-    <PackageReference Include="System.Collections.Immutable" Version="[1.5.0]" />
+    <PackageReference Include="System.Collections.Immutable" Version="[9.0.0]" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net6.0' OR '$(TargetFramework)' == 'net8.0'">