ugh.diff

diff --git a/src/postgres.rs b/src/postgres.rs
index c36c165..7d14b27 100644
--- a/src/postgres.rs
+++ b/src/postgres.rs
@@ -1,4 +1,4 @@
-use byteorder::{BigEndian, ReadBytesExt};
+use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
 use bytes::{BytesMut, BufMut};
 use num::Zero;
 use crate::Decimal;
@@ -156,10 +156,10 @@ impl<'a> FromSql<'a> for Decimal {
 }

 impl ToSql for Decimal {
-    fn to_sql(&self, _: &Type, out: &mut Vec<u8>) -> Result<IsNull, Box<dyn error::Error + 'static + Sync + Send>> {
+    fn to_sql(&self, _: &Type, out: &mut BytesMut) -> Result<IsNull, Box<dyn error::Error + 'static + Sync + Send>> {
         // If it's zero we can short cut with a u64
         if self.is_zero() {
-            out.write_u64::<BigEndian>(0)?;
+            out.put_u64_be(0);
             return Ok(IsNull::No);
         }
         let sign = if self.is_sign_negative() { 0x4000 } else { 0x0000 };
@@ -195,19 +195,24 @@ impl ToSql for Decimal {
             whole_portion_len as i16 - 1
         };

+        let mut v = Vec::new();
+
         // Number of groups
-        out.write_u16::<BigEndian>(num_groups as u16)?;
+        v.write_u16::<BigEndian>(num_groups as u16)?;
         // Weight of first group
-        out.write_i16::<BigEndian>(weight)?;
+        v.write_i16::<BigEndian>(weight)?;
         // Sign
-        out.write_u16::<BigEndian>(sign)?;
+        v.write_u16::<BigEndian>(sign)?;
         // DScale
-        out.write_u16::<BigEndian>(scale)?;
+        v.write_u16::<BigEndian>(scale)?;
+
         // Now process the number
         for group in groups[0..num_groups].iter().rev() {
-            out.write_u16::<BigEndian>(*group)?;
+            v.write_u16::<BigEndian>(*group)?;
         }

+        out.extend_from_slice(v.as_slice());
+
         Ok(IsNull::No)
     }