diff --git a/libguile/gc-card.c b/libguile/gc-card.c
index 0deb1667c..3939417d3 100644
--- a/libguile/gc-card.c
+++ b/libguile/gc-card.c
@@ -308,7 +308,7 @@ scm_i_init_card_freelist (scm_t_cell *  card, SCM *free_list,
   int idx = (card  - seg->bounds[0]) / SCM_GC_CARD_N_CELLS; 
 
   bvec_ptr += idx *SCM_GC_CARD_BVEC_SIZE_IN_LONGS;
-  SCM_GC_CELL_BVEC (card) = bvec_ptr;
+  SCM_GC_SET_CELL_BVEC (card, bvec_ptr);
   
   /*
      ASSUMPTION: n_header_cells <= 2. 
diff --git a/libguile/gc.h b/libguile/gc.h
index bebe856c4..1dca8c2c0 100644
--- a/libguile/gc.h
+++ b/libguile/gc.h
@@ -103,6 +103,7 @@ typedef struct scm_t_cell
 #define SCM_GC_CELL_CARD(x)    ((scm_t_cell *) ((long) (x) & SCM_GC_CARD_ADDR_MASK))
 #define SCM_GC_CELL_OFFSET(x)  (((long) (x) & SCM_GC_CARD_SIZE_MASK) >> SCM_CELL_SIZE_SHIFT)
 #define SCM_GC_CELL_BVEC(x)    SCM_GC_CARD_BVEC (SCM_GC_CELL_CARD (x))
+#define SCM_GC_SET_CELL_BVEC(x, bvec)    SCM_GC_SET_CARD_BVEC (SCM_GC_CELL_CARD (x), bvec)
 #define SCM_GC_CELL_GET_BIT(x) SCM_C_BVEC_GET (SCM_GC_CELL_BVEC (x), SCM_GC_CELL_OFFSET (x))
 #define SCM_GC_CELL_SET_BIT(x) SCM_C_BVEC_SET (SCM_GC_CELL_BVEC (x), SCM_GC_CELL_OFFSET (x))
 #define SCM_GC_CELL_CLEAR_BIT(x) SCM_C_BVEC_CLEAR (SCM_GC_CELL_BVEC (x), SCM_GC_CELL_OFFSET (x))