diff --git a/lib/CanonicalMoments/ext/SymbolicsExt.jl b/lib/CanonicalMoments/ext/SymbolicsExt.jl
index 8949d76..451b742 100644
--- a/lib/CanonicalMoments/ext/SymbolicsExt.jl
+++ b/lib/CanonicalMoments/ext/SymbolicsExt.jl
@@ -1,8 +1,6 @@
 module SymbolicsExt
 using Symbolics
-import Symbolics: unwrap, wrap, array_term
 using CanonicalMoments
-using LinearAlgebra
 
 @register_array_symbolic (alg::CanonicalMoments.EigvalSupportAlg)(M::AbstractMatrix{<:Real}) begin
     size = (size(M)[1],)
@@ -14,26 +12,24 @@ end
     eltype = eltype(M)
 end
 
+# `AbstractVecOrMat` is a `Union` alias, which `@register_array_symbolic` cannot
+# introspect; `AbstractArray` covers both the vector and matrix cases.
 @register_array_symbolic (alg::CanonicalMoments.EigvecWeightAlg)(
     M::AbstractMatrix{<:Real},
-    λ::AbstractVecOrMat{<:Real},
+    λ::AbstractArray{<:Real},
 ) begin
     size = size(M)
     eltype = eltype(M)
 end
 
-function CanonicalMoments._companion_matrix(B::Vector{Num}, C::Vector{Num})
-    dv = -B
-    ndims = length(B)
-    ev = sqrt.(C[2:end]) # Probably use views here
-    _comp_mat_unwrapped = array_term(
-        SymTridiagonal,
-        unwrap.(dv),
-        unwrap.(ev);
-        eltype = Real,
-        size = (ndims, ndims),
-    )
-    return wrap(_comp_mat_unwrapped)
+# Registering the companion matrix constructor keeps it lazy for symbolic inputs
+# while deferring to the numeric implementation otherwise.
+@register_array_symbolic CanonicalMoments._companion_matrix(
+    B::AbstractVector{<:Real},
+    C::AbstractVector{<:Real},
+) begin
+    size = (length(B), length(B))
+    eltype = Real
 end
 
 end