diff --git a/base/threadingconstructs.jl b/base/threadingconstructs.jl
index a5a1294be049b..e202bb0acb317 100644
--- a/base/threadingconstructs.jl
+++ b/base/threadingconstructs.jl
@@ -44,8 +44,9 @@ maxthreadid() = Int(Core.Intrinsics.atomic_pointerref(cglobal(:jl_n_threads, Cin
 """
     Threads.nthreads(:default | :interactive) -> Int
 
-Get the current number of threads within the specified thread pool. The threads in default
-have id numbers `1:nthreads(:default)`.
+Get the current number of threads within the specified thread pool. The threads in `:interactive`
+have id numbers `1:nthreads(:interactive)`, and the threads in `:default` have id numbers in
+`nthreads(:interactive) .+ (1:nthreads(:default))`.
 
 See also `BLAS.get_num_threads` and `BLAS.set_num_threads` in the [`LinearAlgebra`](@ref
 man-linalg) standard library, and `nprocs()` in the [`Distributed`](@ref man-distributed)