diff --git a/decimal_conv.go b/decimal_conv.go
index 7acb8fe..401b229 100644
--- a/decimal_conv.go
+++ b/decimal_conv.go
@@ -27,7 +27,7 @@ func (z *Decimal) SetString(s string) (*Decimal, bool) {
 func (z *Decimal) scan(r io.ByteScanner, base int) (f *Decimal, b int, err error) {
 	prec := z.prec
 	if prec == 0 {
-		prec = _DW
+		prec = DefaultDecimalPrec
 	}
 
 	// A reasonable value in case of an error.
@@ -87,7 +87,7 @@ func (z *Decimal) scan(r io.ByteScanner, base int) (f *Decimal, b int, err error
 		d := int64(fcount)
 		switch b {
 		case 10:
-			exp10 = d
+			exp10 += d
 		case 2:
 			exp2 += d
 		case 8:
diff --git a/decimal_test.go b/decimal_test.go
index e112b7d..26ef8d8 100644
--- a/decimal_test.go
+++ b/decimal_test.go
@@ -18,15 +18,15 @@ var intData = []struct {
 	pr uint
 	e  int32
 }{
-	{"00000000000000000001232", 10, 0, dec{1232000000000000000}, 19, 4},
+	{"00000000000000000001232", 10, 0, dec{1232000000000000000}, DefaultDecimalPrec, 4},
 	{"1234567890123456789_0123456789012345678_9012345678901234567_8901234567890123456_78901234567890", 0, 90,
 		dec{7890123456789000000, 8901234567890123456, 9012345678901234567, 123456789012345678, 1234567890123456789},
 		90, 90},
-	{"1235", 0, 0, dec{1235000000000000000}, _DW, 4},
+	{"1235", 0, 0, dec{1235000000000000000}, DefaultDecimalPrec, 4},
 	{"1235", 0, 3, dec{1240000000000000000}, 3, 4},
 	{"1245", 0, 3, dec{1240000000000000000}, 3, 4},
 	{"12451", 0, 3, dec{1250000000000000000}, 3, 5},
-	{"0", 0, 0, nil, _DW, 0},
+	{"0", 0, 0, nil, DefaultDecimalPrec, 0},
 }
 
 func TestDecimal_dnorm(t *testing.T) {