diff --git a/ChangeLog b/ChangeLog
index 08739594b0..4576deb1cc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Fri Nov 28 02:18:47 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* ext/bigdecimal/bigdecimal.c (BigDecimal_DoDivmod): bigdecimal
+	  division (including modulo) should raise ZeroDivisionError as
+	  integer division. [incompatible]
+
 Fri Nov 28 00:12:00 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* numeric.c (flodivmod): floating point division should raise
diff --git a/ext/bigdecimal/bigdecimal.c b/ext/bigdecimal/bigdecimal.c
index 62ff80a860..b7f5235111 100644
--- a/ext/bigdecimal/bigdecimal.c
+++ b/ext/bigdecimal/bigdecimal.c
@@ -1012,7 +1012,9 @@ BigDecimal_DoDivmod(VALUE self, VALUE r, Real **div, Real **mod)
 
     if(VpIsNaN(a) || VpIsNaN(b)) goto NaN;
     if(VpIsInf(a) || VpIsInf(b)) goto NaN;
-    if(VpIsZero(b))              goto NaN;
+    if(VpIsZero(b)) {
+	rb_raise(rb_eZeroDivError, "divided by 0");
+    }
     if(VpIsZero(a)) {
        GUARD_OBJ(c,VpCreateRbObject(1, "0"));
        GUARD_OBJ(d,VpCreateRbObject(1, "0"));
@@ -1169,9 +1171,6 @@ BigDecimal_div2(int argc, VALUE *argv, VALUE self)
        Real *mod;
        obj = BigDecimal_DoDivmod(self,b,&div,&mod);
        if(obj!=(VALUE)0) return obj;
-       if(VpIsNaN(div) && rb_equal(b, INT2FIX(0))) {
-	   rb_raise(rb_eZeroDivError, "divided by 0");
-       }
        return BigDecimal_to_i(ToValue(div));
     } else {    /* div in BigDecimal sense */
        U_LONG ix = (U_LONG)GetPositiveInt(n);
diff --git a/test/bigdecimal/test_bigdecimal.rb b/test/bigdecimal/test_bigdecimal.rb
index d129d93068..fd5b4afd91 100644
--- a/test/bigdecimal/test_bigdecimal.rb
+++ b/test/bigdecimal/test_bigdecimal.rb
@@ -419,9 +419,7 @@ class TestBigDecimal < Test::Unit::TestCase
     assert_equal([0, 0], BigDecimal.new("0").divmod(2))
 
     BigDecimal.mode(BigDecimal::EXCEPTION_NaN, false)
-    a, b = BigDecimal.new("0").divmod(0)
-    assert_equal(true, a.nan?)
-    assert_equal(true, b.nan?)
+    assert_raise(ZeroDivisionError){BigDecimal.new("0").divmod(0)}
   end
 
   def test_add_bigdecimal