diff --git a/bin/ikarus b/bin/ikarus
index 0aacf55..2f5522e 100755
Binary files a/bin/ikarus and b/bin/ikarus differ
diff --git a/bin/ikarus-numerics.c b/bin/ikarus-numerics.c
index e66ba2d..e04c951 100644
--- a/bin/ikarus-numerics.c
+++ b/bin/ikarus-numerics.c
@@ -1222,12 +1222,8 @@ ikrt_bnfxdivrem(ikp x, ikp y, ikpcb* pcb){
 }
 
 
-
-
-
-
 ikp
-ikrt_bntostring(ikp x, ikpcb* pcb){
+ikrt_bignum_to_bytevector(ikp x, ikpcb* pcb){
   /* FIXME: avoid calling malloc, instead, use the heap pointer itself
    * as a buffer to hold the temporary data after ensuring that it has enough
    * space */
@@ -1258,9 +1254,9 @@ ikrt_bntostring(ikp x, ikpcb* pcb){
     string_start++;
     bytes--;
   }
-  ikp str = ik_alloc(pcb, align(bytes + disp_string_data + (sign_bit?1:0)));
-  ref(str, 0) = fix(bytes + (sign_bit?1:0));
-  ikp dest = str + disp_string_data;
+  ikp bv = ik_alloc(pcb, align(bytes + disp_bytevector_data + (sign_bit?1:0)));
+  ref(bv, 0) = fix(bytes + (sign_bit?1:0));
+  ikp dest = bv + disp_bytevector_data;
   if(sign_bit){
     *dest = '-';
     dest++;
@@ -1274,6 +1270,6 @@ ikrt_bntostring(ikp x, ikpcb* pcb){
     dest[bytes] = 0;
   }
   free(mem);
-  return str + string_tag;
+  return bv + bytevector_tag;
 }
 
diff --git a/src/ikarus.boot b/src/ikarus.boot
index 0940cfb..7b2ef87 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/ikarus.numerics.ss b/src/ikarus.numerics.ss
index 06e1f3f..1a6cd92 100644
--- a/src/ikarus.numerics.ss
+++ b/src/ikarus.numerics.ss
@@ -376,11 +376,16 @@
         [(bignum? x) (even-bignum? x)]
         [else (error 'odd? "~s is not an integer" x)])))
 
+  (define bignum->string
+    (lambda (x)
+      (utf8-bytevector->string
+        (foreign-call "ikrt_bignum_to_bytevector" x))))
+
   (define number->string
     (lambda (x)
       (cond
         [(fixnum? x) (fixnum->string x)]
-        [(bignum? x) (foreign-call "ikrt_bntostring" x)]
+        [(bignum? x) (bignum->string x)]
         [(flonum? x) (flonum->string x)]
         [else (error 'number->string "~s is not a number" x)])))