diff --git a/src/composition.jl b/src/composition.jl
index c8a9ed2e..de644ca1 100644
--- a/src/composition.jl
+++ b/src/composition.jl
@@ -126,19 +126,18 @@ function A_mul_B!(y::AbstractVector, A::CompositeMap, x::AbstractVector)
     if N==1
         A_mul_B!(y, A.maps[1], x)
     else
-        T = eltype(y)
-        dest = Array{T}(undef, size(A.maps[1], 1))
+        dest = similar(y, size(A.maps[1], 1))
         A_mul_B!(dest, A.maps[1], x)
         source = dest
         if N>2
-            dest = Array{T}(undef, size(A.maps[2], 1))
+            dest = similar(y, size(A.maps[2], 1))
         end
         for n in 2:N-1
             try
                 resize!(dest, size(A.maps[n], 1))
             catch err
                 if err == ErrorException("cannot resize array with shared data")
-                    dest = Array{T}(undef, size(A.maps[n], 1))
+                    dest = similar(y, size(A.maps[n], 1))
                 else
                     rethrow(err)
                 end
diff --git a/src/kronecker.jl b/src/kronecker.jl
index 17f9511e..80fd502a 100644
--- a/src/kronecker.jl
+++ b/src/kronecker.jl
@@ -105,9 +105,8 @@ Base.:(==)(A::KroneckerMap, B::KroneckerMap) = (eltype(A) == eltype(B) && A.maps
     na, ma = size(At)
     mb, nb = size(B)
     v = zeros(T, ma)
-    Ty = eltype(y)
-    temp1 = Array{Ty}(undef, na)
-    temp2 = Array{Ty}(undef, nb)
+    temp1 = similar(y, na)
+    temp2 = similar(y, nb)
     @views @inbounds for i in 1:ma
         v[i] = one(T)
         A_mul_B!(temp1, At, v)