diff --git a/iseq.c b/iseq.c
index 7fbb906525..b3c7ad53d3 100644
--- a/iseq.c
+++ b/iseq.c
@@ -427,11 +427,14 @@ rb_iseq_memsize(const rb_iseq_t *iseq)
     return size;
 }
 
+static unsigned long fresh_iseq_unique_id = 0; /* -- Remove In 3.0 -- */
+
 static rb_iseq_t *
 iseq_alloc(void)
 {
     rb_iseq_t *iseq = iseq_imemo_alloc();
     iseq->body = ZALLOC(struct rb_iseq_constant_body);
+    iseq->body->iseq_unique_id = fresh_iseq_unique_id++; /* -- Remove In 3.0 -- */
     return iseq;
 }
 
diff --git a/vm_args.c b/vm_args.c
index 97b1d4ac60..41824527de 100644
--- a/vm_args.c
+++ b/vm_args.c
@@ -593,8 +593,12 @@ VALUE rb_iseq_location(const rb_iseq_t *iseq);
  */
 static st_table *caller_to_callees = 0;
 
-static VALUE rb_warn_check(const rb_execution_context_t * const ec, const void *const callee)
+static VALUE rb_warn_check(const rb_execution_context_t * const ec, const rb_iseq_t *const iseq)
 {
+    if (!iseq) return 0;
+
+    const void *const callee = (void *)iseq->body->iseq_unique_id;
+
     const rb_control_frame_t * const cfp = rb_vm_get_ruby_level_next_cfp(ec, ec->cfp);
 
     if (!cfp) return 0;
diff --git a/vm_core.h b/vm_core.h
index f7ec156cc5..4b1b9e43d0 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -447,6 +447,8 @@ struct rb_iseq_constant_body {
     long unsigned total_calls; /* number of total calls with `mjit_exec()` */
     struct rb_mjit_unit *jit_unit;
 #endif
+
+    unsigned long iseq_unique_id; /* -- Remove In 3.0 -- */
 };
 
 /* T_IMEMO/iseq */