diff --git a/src/GeoStatsFunctions.jl b/src/GeoStatsFunctions.jl
index ed70633..7d6c84f 100644
--- a/src/GeoStatsFunctions.jl
+++ b/src/GeoStatsFunctions.jl
@@ -36,10 +36,7 @@ import LinearAlgebra: ⋅
 # utilities
 include("utils.jl")
 
-# relevant matrices
-include("matrices.jl")
-
-# empirical models
+# empirical estimates
 include("empirical.jl")
 
 # theoretical models
diff --git a/src/empirical.jl b/src/empirical.jl
index 8737152..cd34d86 100644
--- a/src/empirical.jl
+++ b/src/empirical.jl
@@ -2,9 +2,10 @@
 # Licensed under the MIT License. See LICENSE in the project root.
 # ------------------------------------------------------------------
 
+include("empirical/matrices.jl")
 include("empirical/estimators.jl")
 include("empirical/algorithms.jl")
 
 include("empirical/variogram.jl")
-include("empirical/varioplane.jl")
 include("empirical/partition.jl")
+include("empirical/varioplane.jl")
diff --git a/src/matrices.jl b/src/empirical/matrices.jl
similarity index 100%
rename from src/matrices.jl
rename to src/empirical/matrices.jl