--- runtime/Include/bigloo_pair.h.orig	2022-12-29 23:55:22.000000000 -0700
+++ runtime/Include/bigloo_pair.h	2023-01-10 10:19:59.989979958 -0700
@@ -60,7 +60,7 @@ struct bgl_epair {
    obj_t car;       
    obj_t cdr;
    /* extended header type */
-#if( (BGL_GC == BGL_BOEHM_GC) && TAG_PAIR )
+#if( TAG_PAIR )
    obj_t eheader;
 #endif   
    /* extended slot */