diff --git a/src/alloc.c b/src/alloc.c
index 28ca7804ee..a20991e4b9 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -5325,33 +5325,6 @@ make_pure_float (double num)
   return new;
 }
 
-/* Value is a bignum object with value VALUE allocated from pure
-   space.  */
-
-static Lisp_Object
-make_pure_bignum (struct Lisp_Bignum *value)
-{
-  size_t i, nlimbs = mpz_size (value->value);
-  size_t nbytes = nlimbs * sizeof (mp_limb_t);
-  mp_limb_t *pure_limbs;
-  mp_size_t new_size;
-
-  struct Lisp_Bignum *b = pure_alloc (sizeof *b, Lisp_Vectorlike);
-  XSETPVECTYPESIZE (b, PVEC_BIGNUM, 0, VECSIZE (struct Lisp_Bignum));
-
-  pure_limbs = pure_alloc (nbytes, -1);
-  for (i = 0; i < nlimbs; ++i)
-    pure_limbs[i] = mpz_getlimbn (value->value, i);
-
-  new_size = nlimbs;
-  if (mpz_sgn (value->value) < 0)
-    new_size = -new_size;
-
-  mpz_roinit_n (b->value, pure_limbs, new_size);
-
-  return make_lisp_ptr (b, Lisp_Vectorlike);
-}
-
 /* Return a vector with room for LEN Lisp_Objects allocated from
    pure space.  */
 
@@ -5492,8 +5465,6 @@ purecopy (Lisp_Object obj)
       /* Don't hash-cons it.  */
       return obj;
     }
-  else if (BIGNUMP (obj))
-    obj = make_pure_bignum (XBIGNUM (obj));
   else
     {
       AUTO_STRING (fmt, "Don't know how to purify: %S");