diff --git a/src/Iesi.Collections.Test/Iesi.Collections.Test.csproj b/src/Iesi.Collections.Test/Iesi.Collections.Test.csproj
index 1e98a3a..63ed690 100644
--- a/src/Iesi.Collections.Test/Iesi.Collections.Test.csproj
+++ b/src/Iesi.Collections.Test/Iesi.Collections.Test.csproj
@@ -10,12 +10,10 @@
   </PropertyGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'net40'">
-    <PackageReference Include="NUnit" Version="3.14.0" />
-    <PackageReference Include="NUnitLite" Version="3.14.0" />
+    <PackageReference Include="NUnitLite" Version="[3.14.0, 4.0.0)" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' != 'net40'">
-    <PackageReference Include="NUnit" Version="4.1.0" />
     <PackageReference Include="NUnitLite" Version="4.1.0" />
     <PackageReference Include="NUnit.Analyzers" Version="4.1.0">
       <PrivateAssets>all</PrivateAssets>