diff --git a/src/NUnitTestAdapterTests/NUnit.TestAdapter.Tests.csproj b/src/NUnitTestAdapterTests/NUnit.TestAdapter.Tests.csproj
index 6d9dbc46..71cd9a6d 100644
--- a/src/NUnitTestAdapterTests/NUnit.TestAdapter.Tests.csproj
+++ b/src/NUnitTestAdapterTests/NUnit.TestAdapter.Tests.csproj
@@ -13,7 +13,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="NSubstitute" Version="4.3.0" />
+    <PackageReference Include="NSubstitute" Version="4.4.0" />
     <PackageReference Include="NUnit" Version="3.13.3" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="2.10.0" />
     <PackageReference Include="NUnit.Analyzers" Version="3.3.0" />