diff --git a/src/JuliaFEM.jl b/src/JuliaFEM.jl
index c24f838..3090950 100644
--- a/src/JuliaFEM.jl
+++ b/src/JuliaFEM.jl
@@ -147,4 +147,6 @@ export calc_nodal_values!, get_nodal_vector, get_nodal_dict, copy_field!,
        calculate_second_moment_of_mass, extract
 end
 
+include("deprecations.jl")
+
 end
diff --git a/src/assembly.jl b/src/assembly.jl
index 7cdde69..05a04bc 100644
--- a/src/assembly.jl
+++ b/src/assembly.jl
@@ -52,7 +52,7 @@ function assemble!(assembly::Assembly, problem::Problem, elements::Vector{Elemen
     return nothing
 end
 
-function assemble!(problem::Problem, time, ::Type{Val{:mass_matrix}})
+function assemble_mass_matrix!(problem::Problem, time)
     if !isempty(problem.assembly.M)
         info("Mass matrix for $(problem.name) is already assembled, skipping assemble routine")
         return
@@ -73,7 +73,7 @@ function assemble_mass_matrix!{Basis}(problem::Problem, elements::Vector{Element
     ldofs = zeros(Int, nnodes)
     for element in elements
         fill!(M, 0.0)
-        for ip in get_integration_points(element, 1)
+        for ip in get_integration_points(element, 2)
             detJ = element(ip, time, Val{:detJ})
             rho = element("density", time)
             w = ip.weight*rho*detJ
diff --git a/src/deprecations.jl b/src/deprecations.jl
new file mode 100644
index 0000000..a72fb5d
--- /dev/null
+++ b/src/deprecations.jl
@@ -0,0 +1,6 @@
+# This file is a part of JuliaFEM.
+# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
+
+function assemble!(problem::Problem, time, ::Type{Val{:mass_matrix}})
+    assemble_mass_matrix!(problem, time)
+end