diff --git a/Project.toml b/Project.toml
index 7bfdc9d..103aae3 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "ParameterHandling"
 uuid = "2412ca09-6db7-441c-8e3a-88d5709968c5"
 authors = ["Invenia Technical Computing Corporation"]
-version = "0.4.7"
+version = "0.4.8"
 
 [deps]
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"
diff --git a/src/flatten.jl b/src/flatten.jl
index 82d5b60..1414cb0 100644
--- a/src/flatten.jl
+++ b/src/flatten.jl
@@ -19,9 +19,15 @@ function flatten end
 
 flatten(x) = flatten(Float64, x)
 
+function flatten(::Type{T}, ::Nothing) where {T<:Real}
+    v = T[]
+    unflatten_to_Nothing(::Vector{T}) = nothing
+    return v, unflatten_to_Nothing
+end
+
 function flatten(::Type{T}, x::Integer) where {T<:Real}
     v = T[]
-    unflatten_to_Integer(v::Vector{T}) = x
+    unflatten_to_Integer(::Vector{T}) = x
     return v, unflatten_to_Integer
 end
 
diff --git a/test/flatten.jl b/test/flatten.jl
index 47f4707..6b15e42 100644
--- a/test/flatten.jl
+++ b/test/flatten.jl
@@ -8,6 +8,11 @@
         end
     end
 
+    @testset "Nothing" begin
+        test_flatten_interface(nothing)
+        @test isempty(first(flatten(nothing)))
+    end
+
     @testset "AbstractArrays" begin
         test_flatten_interface(randn(10))
         test_flatten_interface(randn(5, 4))