diff --git a/decoder/decoder_compat.go b/decoder/decoder_compat.go
index 466d842e8..84bae4387 100644
--- a/decoder/decoder_compat.go
+++ b/decoder/decoder_compat.go
@@ -112,10 +112,10 @@ func (self *Decoder) CheckTrailings() error {
 func (self *Decoder) Decode(val interface{}) error {
     r := bytes.NewBufferString(self.s)
    dec := json.NewDecoder(r)
-   if (self.f | uint64(OptionUseNumber)) != 0  {
+   if (self.f & uint64(OptionUseNumber)) != 0  {
        dec.UseNumber()
    }
-   if (self.f | uint64(OptionDisableUnknown)) != 0  {
+   if (self.f & uint64(OptionDisableUnknown)) != 0  {
        dec.DisallowUnknownFields()
    }
    return dec.Decode(val)
diff --git a/decoder/decoder_test.go b/decoder/decoder_test.go
index 550147511..882aa7990 100644
--- a/decoder/decoder_test.go
+++ b/decoder/decoder_test.go
@@ -224,6 +224,36 @@ func TestDecodeCorrupt(t *testing.T) {
     }
 }
 
+func TestDecodeOption(t *testing.T) {
+    var s string
+    var d *Decoder
+    var out interface{}
+    var out2 struct {}
+    var err error
+
+    s = "123"
+    d = NewDecoder(s)
+    d.SetOptions(OptionUseNumber);
+    err = d.Decode(&out)
+    assert.NoError(t, err)
+    assert.Equal(t, out.(json.Number), json.Number("123"))
+
+    d = NewDecoder(s)
+    err = d.Decode(&out)
+    assert.NoError(t, err)
+    assert.Equal(t, out.(float64), float64(123))
+
+    s = `{"un": 123}`
+    d = NewDecoder(s)
+    d.SetOptions(OptionDisableUnknown);
+    err = d.Decode(&out2)
+    assert.Error(t, err)
+
+    d = NewDecoder(s)
+    err = d.Decode(&out2)
+    assert.NoError(t, err)
+}
+
 func decode(s string, v interface{}, copy bool) (int, error) {
     d := NewDecoder(s)
     if copy {