diff --git a/test/runtests.jl b/test/runtests.jl
index c5c8b74ea..45c2fc123 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -22,6 +22,7 @@ if GROUP == "All" || GROUP == "Interface"
     @time @safetestset "Validate Boundary Padded Array Concretization" begin include("boundary_padded_array.jl") end
     @time @safetestset "Validate Higher Dimensional Boundary Extension" begin include("multi_dim_bc_test.jl") end
     @time @safetestset "2nd order check" begin include("2nd_order_check.jl") end
+    @time @safetestset "Non-linear Diffusion" begin include("Fast_Diffusion.jl") end
     #@time @safetestset "KdV" begin include("KdV.jl") end # KdV times out and all fails
     #@time @safetestset "Heat Equation" begin include("heat_eqn.jl") end
     @time @safetestset "Matrix-Free Operators" begin include("matrixfree.jl") end