diff --git a/src/problems_elasticity.jl b/src/problems_elasticity.jl
index e3cc30d..6207f4b 100644
--- a/src/problems_elasticity.jl
+++ b/src/problems_elasticity.jl
@@ -766,7 +766,6 @@ end
 #     Plastic material        #
 ###############################
 #=
-include("vonmises.jl")
 abstract PlaneStressLinearElasticPlasticProblem <: LinearElasticityProblem
 
 function PlaneStressLinearElasticPlasticProblem(name="plane stress linear elasticity", dim::Int=2, elements=[])
diff --git a/src/problems_elasticplastic.jl b/src/problems_elasticplastic.jl
index c75df3b..cc1b092 100644
--- a/src/problems_elasticplastic.jl
+++ b/src/problems_elasticplastic.jl
@@ -1,8 +1,6 @@
 # This file is a part of JuliaFEM.
 # License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
 
-include("vonmises.jl")
-
 # Elasticity problems
 abstract ElasticPlasticProblem            <: AbstractProblem
 abstract PlaneStressElasticPlasticProblem <: ElasticPlasticProblem