diff --git a/src/MacroModelling.jl b/src/MacroModelling.jl
index 6c5ed583..2a29f862 100644
--- a/src/MacroModelling.jl
+++ b/src/MacroModelling.jl
@@ -4128,6 +4128,9 @@ function calculate_mean(parameters::Vector{T}, 𝓂::ℳ; verbose::Bool = false,
     
     𝐒₂, solved2 = calculate_second_order_solution(∇₁, ∇₂, 𝐒₁, 𝓂.solution.perturbation.second_order_auxilliary_matrices; T = 𝓂.timings, tol = tol)
 
+    nᵉ = 𝓂.timings.nExo
+    nˢ = 𝓂.timings.nPast_not_future_and_mixed
+
     s_in_s⁺ = BitVector(vcat(𝓂.timings.past_not_future_and_mixed .∈ (dependencies,), zeros(Bool, nᵉ + 1)))
     e_in_s⁺ = BitVector(vcat(zeros(Bool, nˢ + 1), ones(Bool, nᵉ)))
     v_in_s⁺ = BitVector(vcat(zeros(Bool, nˢ), 1, zeros(Bool, nᵉ)))