diff --git a/src/series.jl b/src/series.jl
index 61676b84..3776a74d 100644
--- a/src/series.jl
+++ b/src/series.jl
@@ -15,9 +15,10 @@ prepareSeriesData(x) = error("Cannot convert $(typeof(x)) to series data for plo
 prepareSeriesData(::Nothing) = nothing
 prepareSeriesData(t::Tuple{T, T}) where {T<:Number} = t
 prepareSeriesData(f::Function) = f
-prepareSeriesData(a::AbstractArray{<:MaybeNumber}) = replace(
-                                    x -> ismissing(x) || isinf(x) ? NaN : x,
-                                    map(float,a))
+function prepareSeriesData(a::AbstractArray{<:MaybeNumber})
+    f = isimmutable(a) ? replace : replace!
+    a = f(x -> ismissing(x) || isinf(x) ? NaN : x, map(float, a))
+end
 prepareSeriesData(a::AbstractArray{<:MaybeString}) = replace(x -> ismissing(x) ? "" : x, a)
 prepareSeriesData(s::Surface{<:AMat{<:MaybeNumber}}) = Surface(prepareSeriesData(s.surf))
 prepareSeriesData(s::Surface) = s  # non-numeric Surface, such as an image