diff --git a/Project.toml b/Project.toml
index 7337170..25a1dd4 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "NonconvexUtils"
 uuid = "c48e48a2-1f5e-44ff-8799-c8e168d11d1b"
 authors = ["Mohamed Tarek <mohamed82008@gmail.com> and contributors"]
-version = "0.4.3"
+version = "0.4.4"
 
 [deps]
 AbstractDifferentiation = "c29ec348-61ec-40c8-8164-b8c60e9d9f3d"
@@ -14,6 +14,7 @@ MacroTools = "1914dd2f-81c6-5fcd-8719-6d5c9610ff09"
 NonconvexCore = "035190e5-69f1-488f-aaab-becca2889735"
 SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 SparseDiffTools = "47a9eef4-7e08-11e9-0b38-333d64bd3804"
+SymbolicUtils = "d1185830-fcd6-423d-90d6-eec64667417b"
 Symbolics = "0c5d862f-8b57-4792-8d23-62f2024744c7"
 Zygote = "e88e6eb3-aa80-5325-afca-941959d7151f"
 
@@ -27,6 +28,7 @@ LinearMaps = "3"
 MacroTools = "0.5"
 NonconvexCore = "1.1"
 SparseDiffTools = "2"
+SymbolicUtils = "1.5"
 Symbolics = "5"
 Zygote = "0.5, 0.6"
 julia = "1"
diff --git a/src/sparse_forwarddiff.jl b/src/sparse_forwarddiff.jl
index eb81747..ffa8cb4 100644
--- a/src/sparse_forwarddiff.jl
+++ b/src/sparse_forwarddiff.jl
@@ -212,6 +212,10 @@ struct UnflattennedFunction{F1,F2,V,U} <: Function
     flatteny::Bool
 end
 (f::UnflattennedFunction)(x...) = f.f(x...)
+function NonconvexCore.tovecfunc(f::UnflattennedFunction, ::AbstractVector{<:Real}; flatteny = true)
+    @assert flatteny == f.flatteny
+    return f.flat_f, f.v, f.unflatten
+end
 function NonconvexCore.tovecfunc(f::UnflattennedFunction, x...; flatteny = true)
     @assert flatteny == f.flatteny
     return f.flat_f, f.v, f.unflatten