diff --git a/src/FSharp.Stats/FSharp.Stats.fsproj b/src/FSharp.Stats/FSharp.Stats.fsproj
index a4553f5d..95f40591 100644
--- a/src/FSharp.Stats/FSharp.Stats.fsproj
+++ b/src/FSharp.Stats/FSharp.Stats.fsproj
@@ -183,4 +183,7 @@
   <ItemGroup>
     <None Include="../../README.md" Pack="true" PackagePath="\" />
   </ItemGroup>
+  <ItemGroup>
+    <InternalsVisibleTo Include="FSharp.Stats.Tests" />
+  </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/src/FSharp.Stats/Fitting/GeneralisedLinearModel.fs b/src/FSharp.Stats/Fitting/GeneralisedLinearModel.fs
index 6d5d48fd..80860670 100644
--- a/src/FSharp.Stats/Fitting/GeneralisedLinearModel.fs
+++ b/src/FSharp.Stats/Fitting/GeneralisedLinearModel.fs
@@ -411,8 +411,7 @@ module GLMStatistics =
             }
         )
 
-
-module QRSolver =
+module internal QRSolver =
 
 
     /// Performs a stepwise gain QR calculation for a generalised linear model.