diff --git a/src/distributions/tensor_dirichlet.jl b/src/distributions/tensor_dirichlet.jl
index f9efd689..3440d890 100644
--- a/src/distributions/tensor_dirichlet.jl
+++ b/src/distributions/tensor_dirichlet.jl
@@ -30,6 +30,9 @@ struct TensorDirichlet{T <: Real, N, A <: AbstractArray{T, N}, Ts} <: Continuous
     α0::Ts
     lmnB::Ts
     function TensorDirichlet(alpha::AbstractArray{T, N}) where {T, N}
+        if !all(x -> x > zero(x), alpha)
+            throw(ArgumentError("All elements of the alpha tensor should be positive"))
+        end
         alpha0 = sum(alpha; dims = 1)
         lmnB = sum(loggamma, alpha; dims = 1) - loggamma.(alpha0)
         new{T, N, typeof(alpha), typeof(alpha0)}(alpha, alpha0, lmnB)