diff --git a/src/Metida.jl b/src/Metida.jl
index cbbb91f3..ca1059a6 100644
--- a/src/Metida.jl
+++ b/src/Metida.jl
@@ -72,6 +72,7 @@ include("ml.jl")
 include("fit.jl")
 include("showutils.jl")
 include("statsbase.jl")
+include("statsmodels.jl")
 include("utils.jl")
 include("dof_satter.jl")
 include("dof_contain.jl")
diff --git a/src/statsmodels.jl b/src/statsmodels.jl
new file mode 100644
index 00000000..d5b32a20
--- /dev/null
+++ b/src/statsmodels.jl
@@ -0,0 +1,2 @@
+
+StatsModels.formula(lmm::LMM) = lmm.mf.f
\ No newline at end of file
diff --git a/test/test.jl b/test/test.jl
index a609fdbf..68c31308 100644
--- a/test/test.jl
+++ b/test/test.jl
@@ -108,6 +108,8 @@ include("testdata.jl")
     est = Metida.estimate(lmm, [0,0,0,0,0,1]; level = 0.9)
     est = Metida.estimate(lmm; level = 0.9)
 
+    @test_nowarn formula(lmm)
+
 
     ############################################################################
     # AI like algo