diff --git a/src/base/simulation.jl b/src/base/simulation.jl
index 1799063d4..d05285b1f 100644
--- a/src/base/simulation.jl
+++ b/src/base/simulation.jl
@@ -378,7 +378,7 @@ function _get_diffeq_problem(
     return
 end
 
-function get_history_function(simulation_inputs)
+function get_history_function(simulation_inputs::SimulationInputs)
     x0 = get_initial_conditions(simulation_inputs)
     h(p, t; idxs = nothing) = typeof(idxs) <: Number ? x0[idxs] : x0
     return h