diff --git a/test/Core.Test/Core.Test.csproj b/test/Core.Test/Core.Test.csproj
index 0b9ad16acc..98c9f0c674 100644
--- a/test/Core.Test/Core.Test.csproj
+++ b/test/Core.Test/Core.Test.csproj
@@ -8,7 +8,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
-    <PackageReference Include="NSubstitute" Version="3.1.0" />
+    <PackageReference Include="NSubstitute" Version="4.0.0" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.1">
       <PrivateAssets>all</PrivateAssets>