diff --git a/src/bijectors/simplex.jl b/src/bijectors/simplex.jl
index c5bb4ef6..eacda64e 100644
--- a/src/bijectors/simplex.jl
+++ b/src/bijectors/simplex.jl
@@ -136,6 +136,12 @@ function logabsdetjac(b::SimplexBijector, x::AbstractVector{T}) where {T}
 
     return -lp
 end
+
+# Needed to avoid falling back to `with_logabsdet_jacobian` for matrix inputs.
+function logabsdetjac(b::SimplexBijector, x::AbstractMatrix{<:Real})
+    return sum(Base.Fix1(logabsdetjac, b), eachcol(x))
+end
+
 function simplex_logabsdetjac_gradient(x::AbstractVector)
     T = eltype(x)
     ϵ = _eps(T)
diff --git a/test/interface.jl b/test/interface.jl
index 3272e0f1..c3221307 100644
--- a/test/interface.jl
+++ b/test/interface.jl
@@ -230,6 +230,7 @@ end
         filldist(Exponential(), 2),
         filldist(Exponential(), 2, 3),
         filldist(filldist(Exponential(), 2), 3),
+        filldist(Dirichlet(ones(2)), 3),
     ]
         x = rand(dist)
         b = bijector(dist)