diff --git a/iseq.c b/iseq.c
index 2e13928e92..97047794b1 100644
--- a/iseq.c
+++ b/iseq.c
@@ -3345,6 +3345,7 @@ iseq_type_id(enum rb_iseq_type type)
 static VALUE
 iseq_data_to_ary(const rb_iseq_t *iseq)
 {
+    VALUE iseq_value = (VALUE)iseq;
     unsigned int i;
     long l;
     const struct rb_iseq_constant_body *const iseq_body = ISEQ_BODY(iseq);
@@ -3677,6 +3678,9 @@ iseq_data_to_ary(const rb_iseq_t *iseq)
     rb_ary_push(val, params);
     rb_ary_push(val, exception);
     rb_ary_push(val, body);
+
+    RB_GC_GUARD(iseq_value);
+
     return val;
 }