diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 28b1527ca5f..163c84ae57b 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -1932,17 +1932,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     if !captured_lifetimes.binders_to_ignore.contains(&binder) {
                         match captured_lifetimes.captures.entry(param) {
                             Entry::Occupied(o) => param = self.local_def_id(o.get().1),
-                            Entry::Vacant(v) => {
-                                let p_id = self.next_node_id();
-
-                                let p_def_id = self.create_def(
-                                    captured_lifetimes.parent_def_id,
-                                    p_id,
-                                    DefPathData::LifetimeNs(kw::UnderscoreLifetime),
-                                );
-
-                                v.insert((span, p_id, ParamName::Fresh, res));
-                                param = p_def_id;
+                            Entry::Vacant(_) => {
+                                panic!("Lifetime {:?} should have a def_id at this point", id);
                             }
                         }
                     }