diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs
index ea27db7b81f87..76a755ed9e09d 100644
--- a/compiler/rustc_trait_selection/src/traits/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs
@@ -208,12 +208,14 @@ impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> {
             _ => {
                 // This `for` loop was once a call to `all()`, but this lower-level
                 // form was a perf win. See #64545 for details.
-                for &infer_var in &pending_obligation.stalled_on {
-                    if self.selcx.infcx.ty_or_const_infer_var_changed(infer_var) {
-                        return true;
+                (|| {
+                    for &infer_var in &pending_obligation.stalled_on {
+                        if self.selcx.infcx.ty_or_const_infer_var_changed(infer_var) {
+                            return true;
+                        }
                     }
-                }
-                false
+                    false
+                })()
             }
         }
     }