diff --git a/libguile/integers.c b/libguile/integers.c
index 1d2254745..5653fa8d2 100644
--- a/libguile/integers.c
+++ b/libguile/integers.c
@@ -812,3 +812,65 @@ scm_integer_ceiling_divide_zz (SCM x, SCM y, SCM *qp, SCM *rp)
   *qp = take_mpz (q);
   *rp = take_mpz (r);
 }
+
+SCM
+scm_integer_truncate_quotient_ii (scm_t_inum x, scm_t_inum y)
+{
+  if (y == 0)
+    scm_num_overflow ("truncate-quotient");
+  else
+    {
+      scm_t_inum q = x / y;
+      return long_to_scm (q);
+    }
+}
+
+SCM
+scm_integer_truncate_quotient_iz (scm_t_inum x, SCM y)
+{
+  if (x == SCM_MOST_NEGATIVE_FIXNUM &&
+      bignum_cmp_long (scm_bignum (y), -SCM_MOST_NEGATIVE_FIXNUM) == 0)
+    {
+      /* Special case: x == fixnum-min && y == abs (fixnum-min) */
+      scm_remember_upto_here_1 (y);
+      return SCM_I_MAKINUM (-1);
+    }
+  else
+    return SCM_INUM0;
+}
+
+SCM
+scm_integer_truncate_quotient_zi (SCM x, scm_t_inum y)
+{
+  if (y == 0)
+    scm_num_overflow ("truncate-quotient");
+  else if (y == 1)
+    return x;
+  else
+    {
+      mpz_t q, zx;
+      mpz_init (q);
+      alias_bignum_to_mpz (scm_bignum (x), zx);
+      if (y > 0)
+        mpz_tdiv_q_ui (q, zx, y);
+      else
+        {
+          mpz_tdiv_q_ui (q, zx, -y);
+          mpz_neg (q, q);
+        }
+      scm_remember_upto_here_1 (x);
+      return take_mpz (q);
+    }
+}
+
+SCM
+scm_integer_truncate_quotient_zz (SCM x, SCM y)
+{
+  mpz_t q, zx, zy;
+  mpz_init (q);
+  alias_bignum_to_mpz (scm_bignum (x), zx);
+  alias_bignum_to_mpz (scm_bignum (y), zy);
+  mpz_tdiv_q (q, zx, zy);
+  scm_remember_upto_here_2 (x, y);
+  return take_mpz (q);
+}
diff --git a/libguile/integers.h b/libguile/integers.h
index 331f4aec6..9707444f7 100644
--- a/libguile/integers.h
+++ b/libguile/integers.h
@@ -67,6 +67,11 @@ SCM_INTERNAL void scm_integer_ceiling_divide_zi (SCM x, scm_t_inum y,
 SCM_INTERNAL void scm_integer_ceiling_divide_zz (SCM x, SCM y,
                                                  SCM *qp, SCM *rp);
 
+SCM_INTERNAL SCM scm_integer_truncate_quotient_ii (scm_t_inum x, scm_t_inum y);
+SCM_INTERNAL SCM scm_integer_truncate_quotient_iz (scm_t_inum x, SCM y);
+SCM_INTERNAL SCM scm_integer_truncate_quotient_zi (SCM x, scm_t_inum y);
+SCM_INTERNAL SCM scm_integer_truncate_quotient_zz (SCM x, SCM y);
+
 
 
 #endif  /* SCM_INTEGERS_H */
diff --git a/libguile/numbers.c b/libguile/numbers.c
index 2e73bac1d..7abc727d7 100644
--- a/libguile/numbers.c
+++ b/libguile/numbers.c
@@ -1815,38 +1815,16 @@ SCM_PRIMITIVE_GENERIC (scm_truncate_quotient, "truncate-quotient", 2, 0, 0,
 		       "@end lisp")
 #define FUNC_NAME s_scm_truncate_quotient
 {
-  if (SCM_LIKELY (SCM_I_INUMP (x)))
+  if (SCM_I_INUMP (x))
     {
-      scm_t_inum xx = SCM_I_INUM (x);
-      if (SCM_LIKELY (SCM_I_INUMP (y)))
-	{
-	  scm_t_inum yy = SCM_I_INUM (y);
-	  if (SCM_UNLIKELY (yy == 0))
-	    scm_num_overflow (s_scm_truncate_quotient);
-	  else
-	    {
-	      scm_t_inum qq = xx / yy;
-	      if (SCM_LIKELY (SCM_FIXABLE (qq)))
-		return SCM_I_MAKINUM (qq);
-	      else
-		return scm_i_inum2big (qq);
-	    }
-	}
+      if (SCM_I_INUMP (y))
+        return scm_integer_truncate_quotient_ii (SCM_I_INUM (x),
+                                                 SCM_I_INUM (y));
       else if (SCM_BIGP (y))
-	{
-	  if (SCM_UNLIKELY (xx == SCM_MOST_NEGATIVE_FIXNUM)
-	      && SCM_UNLIKELY (mpz_cmp_ui (SCM_I_BIG_MPZ (y),
-					   - SCM_MOST_NEGATIVE_FIXNUM) == 0))
-	    {
-	      /* Special case: x == fixnum-min && y == abs (fixnum-min) */
-	      scm_remember_upto_here_1 (y);
-	      return SCM_I_MAKINUM (-1);
-	    }
-	  else
-	    return SCM_INUM0;
-	}
+        return scm_integer_truncate_quotient_iz (SCM_I_INUM (x), y);
       else if (SCM_REALP (y))
-	return scm_i_inexact_truncate_quotient (xx, SCM_REAL_VALUE (y));
+	return scm_i_inexact_truncate_quotient (SCM_I_INUM (x),
+                                                SCM_REAL_VALUE (y));
       else if (SCM_FRACTIONP (y))
 	return scm_i_exact_rational_truncate_quotient (x, y);
       else
@@ -1855,36 +1833,10 @@ SCM_PRIMITIVE_GENERIC (scm_truncate_quotient, "truncate-quotient", 2, 0, 0,
     }
   else if (SCM_BIGP (x))
     {
-      if (SCM_LIKELY (SCM_I_INUMP (y)))
-	{
-	  scm_t_inum yy = SCM_I_INUM (y);
-	  if (SCM_UNLIKELY (yy == 0))
-	    scm_num_overflow (s_scm_truncate_quotient);
-	  else if (SCM_UNLIKELY (yy == 1))
-	    return x;
-	  else
-	    {
-	      SCM q = scm_i_mkbig ();
-	      if (yy > 0)
-		mpz_tdiv_q_ui (SCM_I_BIG_MPZ (q), SCM_I_BIG_MPZ (x), yy);
-	      else
-		{
-		  mpz_tdiv_q_ui (SCM_I_BIG_MPZ (q), SCM_I_BIG_MPZ (x), -yy);
-		  mpz_neg (SCM_I_BIG_MPZ (q), SCM_I_BIG_MPZ (q));
-		}
-	      scm_remember_upto_here_1 (x);
-	      return scm_i_normbig (q);
-	    }
-	}
+      if (SCM_I_INUMP (y))
+        return scm_integer_truncate_quotient_zi (x, SCM_I_INUM (y));
       else if (SCM_BIGP (y))
-	{
-	  SCM q = scm_i_mkbig ();
-	  mpz_tdiv_q (SCM_I_BIG_MPZ (q),
-		      SCM_I_BIG_MPZ (x),
-		      SCM_I_BIG_MPZ (y));
-	  scm_remember_upto_here_2 (x, y);
-	  return scm_i_normbig (q);
-	}
+        return scm_integer_truncate_quotient_zz (x, y);
       else if (SCM_REALP (y))
 	return scm_i_inexact_truncate_quotient
 	  (scm_i_big2dbl (x), SCM_REAL_VALUE (y));