diff --git a/src/MacroModelling.jl b/src/MacroModelling.jl
index 763c23f1..3819501d 100644
--- a/src/MacroModelling.jl
+++ b/src/MacroModelling.jl
@@ -6002,7 +6002,7 @@ end
 
 
 
-function calculate_kalman_filter_loglikelihood(𝓂::ℳ, data::AbstractArray{Float64}, observables::Vector{Symbol}; parameters::Vector{U} = nothing, verbose::Bool = false, tol::AbstractFloat = eps()) where U <: Number
+function calculate_kalman_filter_loglikelihood(𝓂::ℳ, data::AbstractArray{Float64}, observables::Vector{Symbol}; parameters::Vector{U} = Float64[], verbose::Bool = false, tol::AbstractFloat = eps()) where U <: Number
     @assert length(observables) == size(data)[1] "Data columns and number of observables are not identical. Make sure the data contains only the selected observables."
     @assert length(observables) <= 𝓂.timings.nExo "Cannot estimate model with more observables than exogenous shocks. Have at least as many shocks as observable variables."