diff --git a/src/czt.jl b/src/czt.jl
index 009e296..4475721 100644
--- a/src/czt.jl
+++ b/src/czt.jl
@@ -139,8 +139,8 @@ julia> zoomed = real.(ift(xft))
   0.0239759   -0.028264    0.0541186  -0.0116475   -0.261294   0.312719  -0.261294  -0.0116475    0.0541186  -0.028264
 ```
 """
-function czt(xin::Array{T,N}, scale, dims=1:length(size(xin)); 
-            remove_wrap=false)::Array{complex(T),N} where {T,N}
+function czt(xin::AbstractArray{T,N}, scale, dims=1:length(size(xin)); 
+            remove_wrap=false)::AbstractArray{complex(T),N} where {T,N}
     xout = xin
     if length(scale) != ndims(xin)
         error("Every of the $(ndims(xin)) dimension needs exactly one corresponding scale (zoom) factor, which should be equal to 1.0 for dimensions not contained in the dims argument.")
diff --git a/test/czt.jl b/test/czt.jl
index fe45364..f5173f8 100644
--- a/test/czt.jl
+++ b/test/czt.jl
@@ -19,6 +19,5 @@ using NDTools # this is needed for the select_region! function below.
         # check if the remove_wrap works
         @test abs(czt(y,zoom; remove_wrap=true)[1,1]) == 0.0
         @test abs(iczt(y,zoom; remove_wrap=true)[1,1]) == 0.0
-        # @vt czt(y,zoom)  select_region(upsample2(ft(y), fix_center=true), new_size=size(y))
     end
 end