diff --git a/sandbox/Weighted Finite State Transducers.jl b/sandbox/Weighted Finite State Transducers.jl
index f012a93b877ae78437fb23e63c35b3ce1a90dfd4..0a3a3a5017b994b350fe40c7bb754e80b56f3ca6 100644
--- a/sandbox/Weighted Finite State Transducers.jl	
+++ b/sandbox/Weighted Finite State Transducers.jl	
@@ -7,7 +7,7 @@ using InteractiveUtils
 # ╔═╡ e2560be8-f3f9-11ed-0754-e3e1572c751d
 begin
 	using Pkg
-	#Pkg.activate(mktempdir())
+	Pkg.activate(mktempdir())
 	
 	# Register the FAST registry
 	Pkg.Registry.add(
diff --git a/src/ops.jl b/src/ops.jl
index 6213b8efdc09090fe283c524d5927ad7cc9a5cc7..a671d9bc8b37d08d1f29bc88b1f5f0fcf25d8db4 100644
--- a/src/ops.jl
+++ b/src/ops.jl
@@ -19,7 +19,7 @@ function closure(A::AbstractWFST; plus = false)
         vcat(TA.V, transpose(α(A)))
     )
     ρB = iszero(ρ(A)) && ! plus ? one(K) : ρ(A)
-    FST(α(A), TB, ω(A), ρB, λ(A))
+    WFST(α(A), TB, ω(A), ρB, λ(A))
 end
 
 """
@@ -37,7 +37,7 @@ function Base.cat(A::AbstractWFST, B::AbstractWFST)
         vcat(blockdiag(TA.V, TB.V), transpose(vcat(spzeros(K, nstates(B)), α(B)))),
     )
 
-    FST(
+    WFST(
         vcat(α(A), ρ(A) * α(B)),
         TC,
         vcat(ω(A) * ρ(B), ω(B)),
@@ -68,7 +68,7 @@ function Base.union(A::AbstractWFST, B::AbstractWFST)
         blockdiag(TA.V, TB.V)
     )
 
-    FST(vcat(α(A), α(B)), TC, vcat(ω(A), ω(B)), ρ(A) ⊕ ρ(B), vcat(λ(A), λ(B)))
+    WFST(vcat(α(A), α(B)), TC, vcat(ω(A), ω(B)), ρ(A) ⊕ ρ(B), vcat(λ(A), λ(B)))
 end
 
 Base.union(A1::AbstractWFST{K}, AN::AbstractWFST{K}...) where K = foldl(union, AN, init = A1)