diff --git a/Project.toml b/Project.toml
index 6fb09fa..1267d77 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "BangBang"
 uuid = "198e06fe-97b7-11e9-32a5-e1d131e6ad66"
 authors = ["Takafumi Arakaki <aka.tkf@gmail.com>"]
-version = "0.4.6"
+version = "0.4.7"
 
 [deps]
 Accessors = "7d9f7c33-5ae7-4f3b-8dc6-eff91059b697"
diff --git a/ext/BangBangStaticArraysExt.jl b/ext/BangBangStaticArraysExt.jl
index c7b0027..9d69ea6 100644
--- a/ext/BangBangStaticArraysExt.jl
+++ b/ext/BangBangStaticArraysExt.jl
@@ -34,5 +34,6 @@ end
 
     BangBang.implements(::BangBang.Mutator, ::Type{<:StaticArrays.StaticArray}) = false
     BangBang.implements(::typeof(setindex!), ::Type{<:StaticArrays.MArray}) = true
+    BangBang.implements(::typeof(setindex!), ::Type{<:StaticArrays.SizedArray}) = true
     BangBang.copyappendable(src::StaticArrays.StaticVector) = src
 end