diff --git a/src/advancedHMC_MCMC.jl b/src/advancedHMC_MCMC.jl
index 2276b47074..df174e2538 100644
--- a/src/advancedHMC_MCMC.jl
+++ b/src/advancedHMC_MCMC.jl
@@ -489,7 +489,7 @@ function ahmc_bayesian_pinn_ode(prob::DiffEqBase.ODEProblem, chain;
     strategy = strategy == GridTraining ? strategy(physdt) : strategy
 
     if dataset != [nothing] &&
-       (length(dataset) < 2 || !(typeof(dataset) <: Vector{<:Vector{<:AbstractFloat}}))
+       (length(dataset) < 2 || !(dataset isa Vector{<:Vector{<:AbstractFloat}}))
         throw(error("Invalid dataset. dataset would be timeseries (x̂,t) where type: Vector{Vector{AbstractFloat}"))
     end
 
diff --git a/src/pinn_types.jl b/src/pinn_types.jl
index 8a4766d122..428f03fc36 100644
--- a/src/pinn_types.jl
+++ b/src/pinn_types.jl
@@ -106,7 +106,7 @@ struct PhysicsInformedNN{T, P, PH, DER, PE, AL, ADA, LOG, K} <: AbstractPINN
                                            log_options = LogOptions(),
                                            iteration = nothing,
                                            kwargs...)
-        multioutput = typeof(chain) <: AbstractArray
+        multioutput = chain isa AbstractArray
 
         if phi === nothing
             if multioutput