Let E 1 ⊂ E 2 ⊂ … be a sequence of locally convex spaces with all identity maps: E n → E n + 1 continuous and E = indlim E n fast complete. Then each set bounded in E is also bounded in some E n iff for any Banach disk B bounded in E and n ∈ N , the closure of B ⋂ E n in B is bounded in some E m . This holds, in particular, if all spaces E n are webbed.