diff --git a/src/Numerics/LinearAlgebra/Builder.cs b/src/Numerics/LinearAlgebra/Builder.cs
index 96e7aee2..a5ffe88a 100644
--- a/src/Numerics/LinearAlgebra/Builder.cs
+++ b/src/Numerics/LinearAlgebra/Builder.cs
@@ -234,7 +234,7 @@ namespace MathNet.Numerics.LinearAlgebra
         Vector<T> SparseVector(int size);
     }
 
-    public static class Builder<T> where T : struct, IEquatable<T>, IFormattable
+    internal static class Builder<T> where T : struct, IEquatable<T>, IFormattable
     {
         static Lazy<IGenericBuilder<T>> _singleton = new Lazy<IGenericBuilder<T>>(Create);
 
diff --git a/src/Numerics/LinearAlgebra/Matrix.cs b/src/Numerics/LinearAlgebra/Matrix.cs
index bb8922ed..623be4a3 100644
--- a/src/Numerics/LinearAlgebra/Matrix.cs
+++ b/src/Numerics/LinearAlgebra/Matrix.cs
@@ -58,7 +58,7 @@ namespace MathNet.Numerics.LinearAlgebra
             ColumnCount = storage.ColumnCount;
         }
 
-        static readonly IGenericBuilder<T> Builder = Builder<T>.Instance;
+        public static readonly IGenericBuilder<T> Builder = Builder<T>.Instance;
 
         /// <summary>
         /// Gets the raw matrix data storage.
diff --git a/src/Numerics/LinearAlgebra/Vector.cs b/src/Numerics/LinearAlgebra/Vector.cs
index ab0c69b2..d272b0c3 100644
--- a/src/Numerics/LinearAlgebra/Vector.cs
+++ b/src/Numerics/LinearAlgebra/Vector.cs
@@ -58,7 +58,7 @@ namespace MathNet.Numerics.LinearAlgebra
             Count = storage.Length;
         }
 
-        static readonly IGenericBuilder<T> Builder = Builder<T>.Instance;
+        public static readonly IGenericBuilder<T> Builder = Builder<T>.Instance;
 
         /// <summary>
         /// Gets the raw vector data storage.