diff --git a/vm_core.h b/vm_core.h
index 9b8aede35c..51b51255b3 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -412,9 +412,9 @@ struct rb_iseq_constant_body {
     struct rb_call_cache *cc_entries; /* size is ci_size = ci_kw_size */
 
     struct {
-      rb_snum_t flip_count;
-      VALUE coverage;
-      VALUE original_iseq;
+	rb_snum_t flip_count;
+	VALUE coverage;
+	VALUE original_iseq;
     } variable;
 
     unsigned int local_table_size;