diff --git a/README.md b/README.md
index a209e0d..84383df 100644
--- a/README.md
+++ b/README.md
@@ -44,7 +44,7 @@ begin
     function FEMBasis.get_reference_element_coordinates(::Type{Tet10})
         return ((0.0, 0.0, 0.0), (1.0, 0.0, 0.0), (0.0, 1.0, 0.0), (0.0, 0.0, 1.0), (0.5, 0.0, 0.0), (0.5, 0.5, 0.0), (0.0, 0.5, 0.0), (0.0, 0.0, 0.5), (0.5, 0.0, 0.5), (0.0, 0.5, 0.5))
     end
-    function FEMBasis.eval_basis!{T}(::Type{Tet10}, N::Matrix{T}, xi::Tuple{T, T, T})
+    function FEMBasis.eval_basis!(::Type{Tet10}, N::Matrix{T}, xi::Tuple{T, T, T}) where T
         (u, v, w) = xi
         begin
             N[1] = 1.0 + -3.0u + -3.0v + -3.0w + 4.0 * (u * v) + 4.0 * (v * w) + 4.0 * (w * u) + 2.0 * u ^ 2 + 2.0 * v ^ 2 + 2.0 * w ^ 2
@@ -60,7 +60,7 @@ begin
         end
         return N
     end
-    function FEMBasis.eval_dbasis!{T}(::Type{Tet10}, dN::Matrix{T}, xi::Tuple{T, T, T})
+    function FEMBasis.eval_dbasis!(::Type{Tet10}, dN::Matrix{T}, xi::Tuple{T, T, T}) where T
         (u, v, w) = xi
         begin
             dN[1, 1] = -3.0 + 4.0v + 4.0w + 2.0 * (2u)
diff --git a/src/create_basis.jl b/src/create_basis.jl
index a9d6781..0ce35f4 100644
--- a/src/create_basis.jl
+++ b/src/create_basis.jl
@@ -101,7 +101,7 @@ function calculate_interpolation_polynomial_derivatives(basis, dim)
     return equations
 end
 
-function create_basis{nbasis,dim}(name::Symbol, description::String, X::NTuple{nbasis, NTuple{dim, Float64}}, basis, dbasis)
+function create_basis(name::Symbol, description::String, X::NTuple{nbasis, NTuple{dim, Float64}}, basis, dbasis) where {nbasis,dim}
 
     Q = Expr(:block)
     for i=1:nbasis
@@ -125,7 +125,7 @@ function create_basis{nbasis,dim}(name::Symbol, description::String, X::NTuple{n
     end
 
     code = quote
-        type $name <: FEMBasis.AbstractBasis
+        mutable struct $name <: FEMBasis.AbstractBasis
         end
 
         function Base.size(::Type{$name})
@@ -145,13 +145,13 @@ function create_basis{nbasis,dim}(name::Symbol, description::String, X::NTuple{n
             return $X
         end
 
-        function FEMBasis.eval_basis!{T}(::Type{$name}, N::Matrix{T}, xi)
+        function FEMBasis.eval_basis!(::Type{$name}, N::Matrix{T}, xi) where T
             $unpack
             $Q
             return N
         end
 
-        function FEMBasis.eval_dbasis!{T}(::Type{$name}, dN::Matrix{T}, xi)
+        function FEMBasis.eval_dbasis!(::Type{$name}, dN::Matrix{T}, xi) where T
             $unpack
             $V
             return dN
@@ -161,24 +161,24 @@ function create_basis{nbasis,dim}(name::Symbol, description::String, X::NTuple{n
     return code
 end
 
-function create_basis{nbasis,dim}(name::Symbol, description::String, X::NTuple{nbasis, NTuple{dim, Float64}}, p::Expr)
+function create_basis(name::Symbol, description::String, X::NTuple{nbasis, NTuple{dim, Float64}}, p::Expr) where {nbasis,dim}
     A = calculate_basis_coefficients(p, X)
     basis = calculate_interpolation_polynomials(p, A)
     dbasis = calculate_interpolation_polynomial_derivatives(basis, dim)
     return create_basis(name, description, X, basis, dbasis)
 end
 
-function create_basis{nbasis,dim}(name::Symbol, description::String, X::NTuple{nbasis, NTuple{dim, Float64}}, p::String)
+function create_basis(name::Symbol, description::String, X::NTuple{nbasis, NTuple{dim, Float64}}, p::String) where {nbasis,dim}
     create_basis(name, description, X, parse(p))
 end
 
-function create_basis{nbasis,dim}(name::Symbol, description::String, X::NTuple{nbasis, NTuple{dim, Float64}}, basis_::NTuple{nbasis, String})
+function create_basis(name::Symbol, description::String, X::NTuple{nbasis, NTuple{dim, Float64}}, basis_::NTuple{nbasis, String}) where {nbasis,dim}
     basis = [parse(b) for b in basis_]
     dbasis = calculate_interpolation_polynomial_derivatives(basis, dim)
     return create_basis(name, description, X, basis, dbasis)
 end
 
-function create_basis{nbasis,dim}(name::Symbol, description::String, X::NTuple{nbasis, NTuple{dim, Float64}}, basis::NTuple{nbasis, Expr})
+function create_basis(name::Symbol, description::String, X::NTuple{nbasis, NTuple{dim, Float64}}, basis::NTuple{nbasis, Expr}) where {nbasis,dim}
     dbasis = calculate_interpolation_polynomial_derivatives(basis, dim)
     return create_basis(name, description, X, basis, dbasis)
 end
diff --git a/src/math.jl b/src/math.jl
index 9413494..30122e7 100644
--- a/src/math.jl
+++ b/src/math.jl
@@ -3,19 +3,19 @@
 
 import Base: length, size
 
-function length{T<:AbstractBasis}(B::T)
+function length(B::T) where T<:AbstractBasis
     return length(T)
 end
 
-function size{T<:AbstractBasis}(B::T)
+function size(B::T) where T<:AbstractBasis
     return size(T)
 end
 
-function eval_basis!{T<:AbstractBasis}(B::T, N, xi)
+function eval_basis!(B::T, N, xi) where T<:AbstractBasis
     return eval_basis!(T, N, xi)
 end
 
-function eval_dbasis!{T<:AbstractBasis}(B::T, dN, xi)
+function eval_dbasis!(B::T, dN, xi) where T<:AbstractBasis
     return eval_dbasis!(T, dN, xi)
 end
 
@@ -145,7 +145,7 @@ end
 """
 Data type for fast FEM.
 """
-type BasisInfo{B<:AbstractBasis,T}
+mutable struct BasisInfo{B<:AbstractBasis,T}
     N::Matrix{T}
     dN::Matrix{T}
     grad::Matrix{T}
@@ -154,11 +154,11 @@ type BasisInfo{B<:AbstractBasis,T}
     detJ::T
 end
 
-function length{T<:AbstractBasis}(B::BasisInfo{T})
+function length(B::BasisInfo{T}) where T<:AbstractBasis
     return length(T)
 end
 
-function size{T<:AbstractBasis}(B::BasisInfo{T})
+function size(B::BasisInfo{T}) where T<:AbstractBasis
     return size(T)
 end
 
@@ -178,7 +178,7 @@ FEMBasis.BasisInfo{FEMBasis.Tri3,Float64}([0.0 0.0 0.0], [0.0 0.0 0.0; 0.0 0.0 0
 ```
 
 """
-function BasisInfo{B<:AbstractBasis}(::Type{B}, T=Float64)
+function BasisInfo(::Type{B}, T=Float64) where B<:AbstractBasis
     dim, nbasis = size(B)
     N = zeros(T, 1, nbasis)
     dN = zeros(T, dim, nbasis)
@@ -207,7 +207,7 @@ FEMBasis.BasisInfo{FEMBasis.Quad4,Float64}([0.25 0.25 0.25 0.25], [-0.25 0.25 0.
 
 ```
 """
-function eval_basis!{B}(bi::BasisInfo{B}, X, xi)
+function eval_basis!(bi::BasisInfo{B}, X, xi) where B
 
     # evaluate basis and derivatives
     eval_basis!(B, bi.N, xi)
@@ -303,7 +303,7 @@ grad!(B, gradu, u)
  1.0  2.0
 ```
 """
-function grad!{B}(bi::BasisInfo{B}, gradu, u)
+function grad!(bi::BasisInfo{B}, gradu, u) where B
     dim, nbasis = size(B)
     fill!(gradu, 0.0)
     for i=1:dim
diff --git a/src/nurbs_segment.jl b/src/nurbs_segment.jl
index 66b7843..d5d186c 100644
--- a/src/nurbs_segment.jl
+++ b/src/nurbs_segment.jl
@@ -2,7 +2,7 @@
 # License is MIT: see https://github.com/JuliaFEM/FEMBasis.jl/blob/master/LICENSE
 
 """ NURBS segment. """
-type NSeg <: AbstractBasis
+mutable struct NSeg <: AbstractBasis
     order :: Int
     knots :: Vector{Float64}
     weights :: Vector{Float64}
diff --git a/src/nurbs_solid.jl b/src/nurbs_solid.jl
index ab9f80b..3f97d46 100644
--- a/src/nurbs_solid.jl
+++ b/src/nurbs_solid.jl
@@ -1,7 +1,7 @@
 # This file is a part of JuliaFEM.
 # License is MIT: see https://github.com/JuliaFEM/FEMBasis.jl/blob/master/LICENSE
 
-type NSolid <: AbstractBasis
+mutable struct NSolid <: AbstractBasis
     order_u :: Int
     order_v :: Int
     order_w :: Int
diff --git a/src/nurbs_surface.jl b/src/nurbs_surface.jl
index 9c0e124..e631ccd 100644
--- a/src/nurbs_surface.jl
+++ b/src/nurbs_surface.jl
@@ -1,7 +1,7 @@
 # This file is a part of JuliaFEM.
 # License is MIT: see https://github.com/JuliaFEM/FEMBasis.jl/blob/master/LICENSE
 
-type NSurf <: AbstractBasis
+mutable struct NSurf <: AbstractBasis
     order_u :: Int
     order_v :: Int
     knots_u :: Vector{Float64}