--- runtime/Include/bigloo_pair.h.orig 2020-05-12 00:35:36.000000000 -0600
+++ runtime/Include/bigloo_pair.h 2020-10-13 17:39:33.656637491 -0600
@@ -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 */