diff --git a/base/random.jl b/base/random.jl
index a5dc16e114125..a60eef4778a50 100644
--- a/base/random.jl
+++ b/base/random.jl
@@ -1194,6 +1194,7 @@ Fill the array `A` with random numbers following the exponential distribution (w
 """
 function randexp! end
 
+# TODO(#17627): Consider adding BigFloat support to these functions as well.
 let Floats = Union{Float16,Float32,Float64}
     for randfun in [:randn, :randexp]
         randfun! = Symbol(randfun, :!)
diff --git a/test/random.jl b/test/random.jl
index 2da4a435cb2c7..a20ebf7d77d93 100644
--- a/test/random.jl
+++ b/test/random.jl
@@ -351,6 +351,7 @@ for rng in ([], [MersenneTwister()], [RandomDevice()])
         @test_throws MethodError r(Bool)
         @test_throws MethodError r(String)
         @test_throws MethodError r(AbstractFloat)
+        # TODO(#17627): Consider adding support for randn(BigFloat) and removing this test.
         @test_throws MethodError r(BigFloat)
 
         @test_throws MethodError r(Int64, (2,3))