diff --git a/base/reflection.jl b/base/reflection.jl
index f114949ba6fd3..b2eef3f920fe4 100644
--- a/base/reflection.jl
+++ b/base/reflection.jl
@@ -680,7 +680,11 @@ issingletontype(@nospecialize(t)) = (@_pure_meta; isa(t, DataType) && isdefined(
 Compute a type that contains the intersection of `T` and `S`. Usually this will be the
 smallest such type or one close to it.
 """
-typeintersect(@nospecialize(a), @nospecialize(b)) = (@_pure_meta; ccall(:jl_type_intersection, Any, (Any, Any), a, b))
+function typeintersect(@nospecialize(a), @nospecialize(b))
+    @_pure_meta
+    (!isvarargtype(a) && !isvarargtype(b)) || throw(ArgumentError("invalid typeintersect with Vararg"))
+    return ccall(:jl_type_intersection, Any, (Any, Any), a, b)
+end
 
 morespecific(@nospecialize(a), @nospecialize(b)) = ccall(:jl_type_morespecific, Cint, (Any, Any), a, b) != 0
 
diff --git a/test/subtype.jl b/test/subtype.jl
index 3eca685aee84c..c8c5e091acf65 100644
--- a/test/subtype.jl
+++ b/test/subtype.jl
@@ -1976,3 +1976,6 @@ end
 @testintersect(Tuple{Type{Pair{_A, S} where S<:AbstractArray{<:_A, 2}}, Dict} where _A,
                Tuple{Type{Pair{_A, S} where S<:AbstractArray{<:_A, 2}} where _A, Union{Array, Pair}},
                Bottom)
+
+@test_throws ArgumentError typeintersect(Vararg{Int}, Int)
+@test_throws ArgumentError typeintersect(Int, Vararg{Int})