diff --git a/test/subtype.jl b/test/subtype.jl
index aa2a5a92fee46..92e9d0c75f35c 100644
--- a/test/subtype.jl
+++ b/test/subtype.jl
@@ -1811,3 +1811,6 @@ end
 @testintersect(Type{T} where T>:Missing,
                Type{Some{T}} where T,
                Union{})
+
+# issue #24333
+@test_broken (Type{Union{Ref,Cvoid}} <: Type{Union{T,Cvoid}} where T)