diff --git a/src/utilities.jl b/src/utilities.jl
index 5a426bd17..3e967c2d7 100644
--- a/src/utilities.jl
+++ b/src/utilities.jl
@@ -162,12 +162,16 @@ _FType(::Type{Int32}) = Float32
 _FType(::Type{Int64}) = Float64
 _FType(::Type{Float32}) = Float32
 _FType(::Type{Float64}) = Float64
-_FType(::Type{ComplexF32}) = Float32
-_FType(::Type{ComplexF64}) = Float64
+_FType(::Type{Complex{Int32}}) = Float32
+_FType(::Type{Complex{Int64}}) = Float64
+_FType(::Type{Complex{Float32}}) = Float32
+_FType(::Type{Complex{Float64}}) = Float64
 _CType(::AbstractArray{T}) where {T<:Number} = _CType(T)
 _CType(::Type{Int32}) = ComplexF32
 _CType(::Type{Int64}) = ComplexF64
 _CType(::Type{Float32}) = ComplexF32
 _CType(::Type{Float64}) = ComplexF64
-_CType(::Type{ComplexF32}) = ComplexF32
-_CType(::Type{ComplexF64}) = ComplexF64
+_CType(::Type{Complex{Int32}}) = ComplexF32
+_CType(::Type{Complex{Int64}}) = ComplexF64
+_CType(::Type{Complex{Float32}}) = ComplexF32
+_CType(::Type{Complex{Float64}}) = ComplexF64