diff -r 6dfa8001eed2 -r f8be66557e0f src/ZipArrays.jl
--- a/src/ZipArrays.jl	Wed Dec 15 01:09:09 2021 +0200
+++ b/src/ZipArrays.jl	Wed Dec 22 11:13:38 2021 +0200
@@ -36,21 +36,21 @@
 
 A way to refer to a `ZipArray` without specifying the container types.
 """
-AbstractZipArray{S,T,N} = ZipArray{S,T,N,A,B} where {A <: AbstractArray{S,N}, B <: AbstractArray{T,N}}
+const AbstractZipArray{S,T,N} = ZipArray{S,T,N,A,B} where {A <: AbstractArray{S,N}, B <: AbstractArray{T,N}}
 
 """
 `ZipVector{S,T,A,B}`
 
 One-dimensional `ZipArray`.
 """
-ZipVector{S,T,A,B} = ZipArray{S,T,1,A,B}
+const ZipVector{S,T,A,B} = ZipArray{S,T,1,A,B}
 
 """
 `AbstractZipVector{S,T}`
 
 One-dimensional `AbstractZipArray`.
 """
-AbstractZipVector{S,T} = AbstractZipArray{S,T,1}
+const AbstractZipVector{S,T} = AbstractZipArray{S,T,1}
 
 
 function Base.IndexStyle( :: Type{<:ZipArray{S,T,N,A,B}}) where {S,T,N,A,B}