diff --git a/src/counts.jl b/src/counts.jl
index d7485fd3..7cbb7a0a 100644
--- a/src/counts.jl
+++ b/src/counts.jl
@@ -450,5 +450,13 @@ Return a dictionary mapping each unique value in `x` to its proportion in `x`.
 If a vector of weights `wv` is provided, the proportion of weights is computed rather
 than the proportion of raw counts.
 """
-proportionmap(x::AbstractArray) = _normalize_countmap(countmap(x), length(x))
+function proportionmap(x)
+    countm = Dict{eltype(x), Int}()
+    n = 0
+    for y in x
+        countm[y] = get(countm, y, 0) + 1
+        n += 1
+    end
+    _normalize_countmap(countm, n)
+end
 proportionmap(x::AbstractArray, wv::AbstractWeights) = _normalize_countmap(countmap(x, wv), sum(wv))
diff --git a/test/counts.jl b/test/counts.jl
index 262f2bbd..fa30969c 100644
--- a/test/counts.jl
+++ b/test/counts.jl
@@ -209,3 +209,10 @@ if VERSION >= v"1.9.0-DEV"
         # countmap and proportionmap only support the :dict algorithm for weighted sums.
     end
 end
+
+@testset "proportionmap with iterator" begin
+    a = [1, 2, 3, 4]
+    b =[true, true ,false, false, true, false]
+    @test proportionmap(skipmissing(a)) == Dict(1 => 0.25, 2 => 0.25, 3 => 0.25, 4 => 0.25)
+    @test proportionmap(skipmissing(b)) == Dict(true => 0.5, false => 0.5)
+end