diff --git a/crates/swc_ecma_minifier/src/compress/optimize/mod.rs b/crates/swc_ecma_minifier/src/compress/optimize/mod.rs
index 2fa8a5e60b2e..df38153d2a18 100644
--- a/crates/swc_ecma_minifier/src/compress/optimize/mod.rs
+++ b/crates/swc_ecma_minifier/src/compress/optimize/mod.rs
@@ -2990,11 +2990,11 @@ impl VisitMut for Optimizer<'_> {
                 return false;
             }
 
+            debug_assert_valid(&*var);
+
             true
         });
 
-        debug_assert_valid(&*vars);
-
         let uses_eval = self.data.scopes.get(&self.ctx.scope).unwrap().has_eval_call;
 
         if !uses_eval && !self.ctx.dont_use_prepend_nor_append {