diff --git a/src/mir/builder.rs b/src/mir/builder.rs
index b45d988d..f4c1fe6a 100644
--- a/src/mir/builder.rs
+++ b/src/mir/builder.rs
@@ -734,7 +734,8 @@ impl MirBuilder {
             args.push(ty_id);
             args.extend(arg_vals);
             // Call env.box.new
-            let dst = self.value_gen.next();
+            // 📦 Hotfix 3: Use next_value_id() to respect function parameter reservation
+            let dst = self.next_value_id();
             self.emit_instruction(MirInstruction::ExternCall {
                 dst: Some(dst),
                 iface_name: "env.box".to_string(),
@@ -755,7 +756,8 @@ impl MirBuilder {
                 ..
             } = arguments[0].clone()
             {
-                let dst = self.value_gen.next();
+                // 📦 Hotfix 3: Use next_value_id() to respect function parameter reservation
+                let dst = self.next_value_id();
                 self.emit_instruction(MirInstruction::Const {
                     dst,
                     value: ConstValue::Integer(n),
@@ -773,7 +775,8 @@ impl MirBuilder {
         }
 
         // Generate the destination ValueId
-        let dst = self.value_gen.next();
+        // 📦 Hotfix 3: Use next_value_id() to respect function parameter reservation
+        let dst = self.next_value_id();
 
         // Emit NewBox instruction for all Box types
         // VM will handle optimization for basic types internally