diff --git a/compiler/solve/src/solve.rs b/compiler/solve/src/solve.rs
index 72930cd335..7bbf7d5751 100644
--- a/compiler/solve/src/solve.rs
+++ b/compiler/solve/src/solve.rs
@@ -1105,32 +1105,7 @@ fn solve(
                 let actual =
                     either_type_index_to_var(constraints, subs, rank, pools, aliases, *type_index);
 
-                let mut stack = vec![actual];
-                while let Some(var) = stack.pop() {
-                    use {Content::*, FlatType::*};
-
-                    let mut desc = subs.get(var);
-                    if let Structure(TagUnion(tags, ext)) = desc.content {
-                        if let Structure(EmptyTagUnion) = subs.get_content_without_compacting(ext) {
-                            let new_ext = subs.fresh_unnamed_flex_var();
-                            subs.set_rank(new_ext, desc.rank);
-                            let new_union = Structure(TagUnion(tags, new_ext));
-                            desc.content = new_union;
-                            subs.set(var, desc);
-                        }
-
-                        // Also open up all nested tag unions.
-                        let all_vars = tags.variables().into_iter();
-                        stack.extend(all_vars.flat_map(|slice| subs[slice]).map(|var| subs[var]));
-                    }
-
-                    // Today, an "open" constraint doesn't affect any types
-                    // other than tag unions. Recursive tag unions are constructed
-                    // at a later time (during occurs checks after tag unions are
-                    // resolved), so that's not handled here either.
-                    // NB: Handle record types here if we add presence constraints
-                    // to their type inference as well.
-                }
+                open_tag_union(subs, actual);
 
                 state
             }