diff --git a/.circleci/config.yml b/.circleci/config.yml
index 47efb05d..9ea84498 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -22,7 +22,7 @@ version: 2
 jobs:
   build:
     docker:
-      - image: rust:1.30.1
+      - image: rust:1.31.0
         environment:
           RUSTFLAGS: -D warnings
       - image: sfackler/rust-postgres-test:5
diff --git a/postgres-protocol/Cargo.toml b/postgres-protocol/Cargo.toml
index 72194ac7..2c8157e5 100644
--- a/postgres-protocol/Cargo.toml
+++ b/postgres-protocol/Cargo.toml
@@ -2,6 +2,7 @@
 name = "postgres-protocol"
 version = "0.3.2"
 authors = ["Steven Fackler <sfackler@gmail.com>"]
+edition = "2018"
 description = "Low level Postgres protocol APIs"
 license = "MIT/Apache-2.0"
 repository = "https://github.com/sfackler/rust-postgres-protocol"
diff --git a/postgres-protocol/src/authentication/sasl.rs b/postgres-protocol/src/authentication/sasl.rs
index cd46d67d..8488fa3c 100644
--- a/postgres-protocol/src/authentication/sasl.rs
+++ b/postgres-protocol/src/authentication/sasl.rs
@@ -1,6 +1,5 @@
 //! SASL-based authentication support.
 
-use base64;
 use generic_array::typenum::U32;
 use generic_array::GenericArray;
 use hmac::{Hmac, Mac};
@@ -11,7 +10,6 @@ use std::io;
 use std::iter;
 use std::mem;
 use std::str;
-use stringprep;
 
 const NONCE_LENGTH: usize = 24;
 
@@ -143,7 +141,8 @@ impl ScramSha256 {
                     v = 0x7e
                 }
                 v as char
-            }).collect::<String>();
+            })
+            .collect::<String>();
 
         ScramSha256::new_inner(password, channel_binding, nonce)
     }
@@ -333,7 +332,7 @@ impl<'a> Parser<'a> {
 
     fn printable(&mut self) -> io::Result<&'a str> {
         self.take_while(|c| match c {
-            '\x21'...'\x2b' | '\x2d'...'\x7e' => true,
+            '\x21'..='\x2b' | '\x2d'..='\x7e' => true,
             _ => false,
         })
     }
@@ -346,7 +345,7 @@ impl<'a> Parser<'a> {
 
     fn base64(&mut self) -> io::Result<&'a str> {
         self.take_while(|c| match c {
-            'a'...'z' | 'A'...'Z' | '0'...'9' | '/' | '+' | '=' => true,
+            'a'..='z' | 'A'..='Z' | '0'..='9' | '/' | '+' | '=' => true,
             _ => false,
         })
     }
@@ -359,7 +358,7 @@ impl<'a> Parser<'a> {
 
     fn posit_number(&mut self) -> io::Result<u32> {
         let n = self.take_while(|c| match c {
-            '0'...'9' => true,
+            '0'..='9' => true,
             _ => false,
         })?;
         n.parse()
diff --git a/postgres-protocol/src/lib.rs b/postgres-protocol/src/lib.rs
index da06a4c3..aa815c36 100644
--- a/postgres-protocol/src/lib.rs
+++ b/postgres-protocol/src/lib.rs
@@ -10,18 +10,7 @@
 //! This library assumes that the `client_encoding` backend parameter has been
 //! set to `UTF8`. It will most likely not behave properly if that is not the case.
 #![doc(html_root_url = "https://docs.rs/postgres-protocol/0.3")]
-#![warn(missing_docs)]
-extern crate base64;
-extern crate byteorder;
-extern crate bytes;
-extern crate fallible_iterator;
-extern crate generic_array;
-extern crate hmac;
-extern crate md5;
-extern crate memchr;
-extern crate rand;
-extern crate sha2;
-extern crate stringprep;
+#![warn(missing_docs, rust_2018_idioms)]
 
 use byteorder::{BigEndian, ByteOrder};
 use std::io;
diff --git a/postgres-protocol/src/message/backend.rs b/postgres-protocol/src/message/backend.rs
index eacb5da4..c11516d1 100644
--- a/postgres-protocol/src/message/backend.rs
+++ b/postgres-protocol/src/message/backend.rs
@@ -9,7 +9,7 @@ use std::io::{self, Read};
 use std::ops::Range;
 use std::str;
 
-use Oid;
+use crate::Oid;
 
 /// An enum representing Postgres backend messages.
 pub enum Message {
diff --git a/postgres-protocol/src/message/frontend.rs b/postgres-protocol/src/message/frontend.rs
index a0c20a83..edb929ef 100644
--- a/postgres-protocol/src/message/frontend.rs
+++ b/postgres-protocol/src/message/frontend.rs
@@ -6,7 +6,7 @@ use std::error::Error;
 use std::io;
 use std::marker;
 
-use {write_nullable, FromUsize, IsNull, Oid};
+use crate::{write_nullable, FromUsize, IsNull, Oid};
 
 pub enum Message<'a> {
     Bind {
@@ -148,13 +148,13 @@ where
 }
 
 pub enum BindError {
-    Conversion(Box<Error + marker::Sync + Send>),
+    Conversion(Box<dyn Error + marker::Sync + Send>),
     Serialization(io::Error),
 }
 
-impl From<Box<Error + marker::Sync + Send>> for BindError {
+impl From<Box<dyn Error + marker::Sync + Send>> for BindError {
     #[inline]
-    fn from(e: Box<Error + marker::Sync + Send>) -> BindError {
+    fn from(e: Box<dyn Error + marker::Sync + Send>) -> BindError {
         BindError::Conversion(e)
     }
 }
@@ -179,7 +179,7 @@ pub fn bind<I, J, F, T, K>(
 where
     I: IntoIterator<Item = i16>,
     J: IntoIterator<Item = T>,
-    F: FnMut(T, &mut Vec<u8>) -> Result<IsNull, Box<Error + marker::Sync + Send>>,
+    F: FnMut(T, &mut Vec<u8>) -> Result<IsNull, Box<dyn Error + marker::Sync + Send>>,
     K: IntoIterator<Item = i16>,
 {
     buf.push(b'B');
@@ -225,7 +225,8 @@ pub fn cancel_request(process_id: i32, secret_key: i32, buf: &mut Vec<u8>) {
         buf.write_i32::<BigEndian>(80877102).unwrap();
         buf.write_i32::<BigEndian>(process_id).unwrap();
         buf.write_i32::<BigEndian>(secret_key)
-    }).unwrap();
+    })
+    .unwrap();
 }
 
 #[inline]
diff --git a/postgres-protocol/src/types.rs b/postgres-protocol/src/types.rs
index 1066ee6a..b5d65cb3 100644
--- a/postgres-protocol/src/types.rs
+++ b/postgres-protocol/src/types.rs
@@ -5,7 +5,7 @@ use std::boxed::Box as StdBox;
 use std::error::Error;
 use std::str;
 
-use {write_nullable, FromUsize, IsNull, Oid};
+use crate::{write_nullable, FromUsize, IsNull, Oid};
 
 const RANGE_UPPER_UNBOUNDED: u8 = 0b0001_0000;
 const RANGE_LOWER_UNBOUNDED: u8 = 0b0000_1000;
@@ -21,7 +21,7 @@ pub fn bool_to_sql(v: bool, buf: &mut Vec<u8>) {
 
 /// Deserializes a `BOOL` value.
 #[inline]
-pub fn bool_from_sql(buf: &[u8]) -> Result<bool, StdBox<Error + Sync + Send>> {
+pub fn bool_from_sql(buf: &[u8]) -> Result<bool, StdBox<dyn Error + Sync + Send>> {
     if buf.len() != 1 {
         return Err("invalid buffer size".into());
     }
@@ -49,7 +49,7 @@ pub fn text_to_sql(v: &str, buf: &mut Vec<u8>) {
 
 /// Deserializes a `TEXT`, `VARCHAR`, `CHAR(n)`, `NAME`, or `CITEXT` value.
 #[inline]
-pub fn text_from_sql(buf: &[u8]) -> Result<&str, StdBox<Error + Sync + Send>> {
+pub fn text_from_sql(buf: &[u8]) -> Result<&str, StdBox<dyn Error + Sync + Send>> {
     Ok(str::from_utf8(buf)?)
 }
 
@@ -61,7 +61,7 @@ pub fn char_to_sql(v: i8, buf: &mut Vec<u8>) {
 
 /// Deserializes a `"char"` value.
 #[inline]
-pub fn char_from_sql(mut buf: &[u8]) -> Result<i8, StdBox<Error + Sync + Send>> {
+pub fn char_from_sql(mut buf: &[u8]) -> Result<i8, StdBox<dyn Error + Sync + Send>> {
     let v = buf.read_i8()?;
     if !buf.is_empty() {
         return Err("invalid buffer size".into());
@@ -77,7 +77,7 @@ pub fn int2_to_sql(v: i16, buf: &mut Vec<u8>) {
 
 /// Deserializes an `INT2` value.
 #[inline]
-pub fn int2_from_sql(mut buf: &[u8]) -> Result<i16, StdBox<Error + Sync + Send>> {
+pub fn int2_from_sql(mut buf: &[u8]) -> Result<i16, StdBox<dyn Error + Sync + Send>> {
     let v = buf.read_i16::<BigEndian>()?;
     if !buf.is_empty() {
         return Err("invalid buffer size".into());
@@ -93,7 +93,7 @@ pub fn int4_to_sql(v: i32, buf: &mut Vec<u8>) {
 
 /// Deserializes an `INT4` value.
 #[inline]
-pub fn int4_from_sql(mut buf: &[u8]) -> Result<i32, StdBox<Error + Sync + Send>> {
+pub fn int4_from_sql(mut buf: &[u8]) -> Result<i32, StdBox<dyn Error + Sync + Send>> {
     let v = buf.read_i32::<BigEndian>()?;
     if !buf.is_empty() {
         return Err("invalid buffer size".into());
@@ -109,7 +109,7 @@ pub fn oid_to_sql(v: Oid, buf: &mut Vec<u8>) {
 
 /// Deserializes an `OID` value.
 #[inline]
-pub fn oid_from_sql(mut buf: &[u8]) -> Result<Oid, StdBox<Error + Sync + Send>> {
+pub fn oid_from_sql(mut buf: &[u8]) -> Result<Oid, StdBox<dyn Error + Sync + Send>> {
     let v = buf.read_u32::<BigEndian>()?;
     if !buf.is_empty() {
         return Err("invalid buffer size".into());
@@ -125,7 +125,7 @@ pub fn int8_to_sql(v: i64, buf: &mut Vec<u8>) {
 
 /// Deserializes an `INT8` value.
 #[inline]
-pub fn int8_from_sql(mut buf: &[u8]) -> Result<i64, StdBox<Error + Sync + Send>> {
+pub fn int8_from_sql(mut buf: &[u8]) -> Result<i64, StdBox<dyn Error + Sync + Send>> {
     let v = buf.read_i64::<BigEndian>()?;
     if !buf.is_empty() {
         return Err("invalid buffer size".into());
@@ -141,7 +141,7 @@ pub fn float4_to_sql(v: f32, buf: &mut Vec<u8>) {
 
 /// Deserializes a `FLOAT4` value.
 #[inline]
-pub fn float4_from_sql(mut buf: &[u8]) -> Result<f32, StdBox<Error + Sync + Send>> {
+pub fn float4_from_sql(mut buf: &[u8]) -> Result<f32, StdBox<dyn Error + Sync + Send>> {
     let v = buf.read_f32::<BigEndian>()?;
     if !buf.is_empty() {
         return Err("invalid buffer size".into());
@@ -157,7 +157,7 @@ pub fn float8_to_sql(v: f64, buf: &mut Vec<u8>) {
 
 /// Deserializes a `FLOAT8` value.
 #[inline]
-pub fn float8_from_sql(mut buf: &[u8]) -> Result<f64, StdBox<Error + Sync + Send>> {
+pub fn float8_from_sql(mut buf: &[u8]) -> Result<f64, StdBox<dyn Error + Sync + Send>> {
     let v = buf.read_f64::<BigEndian>()?;
     if !buf.is_empty() {
         return Err("invalid buffer size".into());
@@ -167,7 +167,7 @@ pub fn float8_from_sql(mut buf: &[u8]) -> Result<f64, StdBox<Error + Sync + Send
 
 /// Serializes an `HSTORE` value.
 #[inline]
-pub fn hstore_to_sql<'a, I>(values: I, buf: &mut Vec<u8>) -> Result<(), StdBox<Error + Sync + Send>>
+pub fn hstore_to_sql<'a, I>(values: I, buf: &mut Vec<u8>) -> Result<(), StdBox<dyn Error + Sync + Send>>
 where
     I: IntoIterator<Item = (&'a str, Option<&'a str>)>,
 {
@@ -194,7 +194,7 @@ where
     Ok(())
 }
 
-fn write_pascal_string(s: &str, buf: &mut Vec<u8>) -> Result<(), StdBox<Error + Sync + Send>> {
+fn write_pascal_string(s: &str, buf: &mut Vec<u8>) -> Result<(), StdBox<dyn Error + Sync + Send>> {
     let size = i32::from_usize(s.len())?;
     buf.write_i32::<BigEndian>(size).unwrap();
     buf.extend_from_slice(s.as_bytes());
@@ -205,7 +205,7 @@ fn write_pascal_string(s: &str, buf: &mut Vec<u8>) -> Result<(), StdBox<Error +
 #[inline]
 pub fn hstore_from_sql<'a>(
     mut buf: &'a [u8],
-) -> Result<HstoreEntries<'a>, StdBox<Error + Sync + Send>> {
+) -> Result<HstoreEntries<'a>, StdBox<dyn Error + Sync + Send>> {
     let count = buf.read_i32::<BigEndian>()?;
     if count < 0 {
         return Err("invalid entry count".into());
@@ -225,10 +225,10 @@ pub struct HstoreEntries<'a> {
 
 impl<'a> FallibleIterator for HstoreEntries<'a> {
     type Item = (&'a str, Option<&'a str>);
-    type Error = StdBox<Error + Sync + Send>;
+    type Error = StdBox<dyn Error + Sync + Send>;
 
     #[inline]
-    fn next(&mut self) -> Result<Option<(&'a str, Option<&'a str>)>, StdBox<Error + Sync + Send>> {
+    fn next(&mut self) -> Result<Option<(&'a str, Option<&'a str>)>, StdBox<dyn Error + Sync + Send>> {
         if self.remaining == 0 {
             if !self.buf.is_empty() {
                 return Err("invalid buffer size".into());
@@ -272,7 +272,7 @@ pub fn varbit_to_sql<I>(
     len: usize,
     v: I,
     buf: &mut Vec<u8>,
-) -> Result<(), StdBox<Error + Sync + Send>>
+) -> Result<(), StdBox<dyn Error + Sync + Send>>
 where
     I: Iterator<Item = u8>,
 {
@@ -288,7 +288,7 @@ where
 
 /// Deserializes a `VARBIT` or `BIT` value.
 #[inline]
-pub fn varbit_from_sql<'a>(mut buf: &'a [u8]) -> Result<Varbit<'a>, StdBox<Error + Sync + Send>> {
+pub fn varbit_from_sql<'a>(mut buf: &'a [u8]) -> Result<Varbit<'a>, StdBox<dyn Error + Sync + Send>> {
     let len = buf.read_i32::<BigEndian>()?;
     if len < 0 {
         return Err("invalid varbit length".into());
@@ -336,7 +336,7 @@ pub fn timestamp_to_sql(v: i64, buf: &mut Vec<u8>) {
 ///
 /// The value represents the number of microseconds since midnight, January 1st, 2000.
 #[inline]
-pub fn timestamp_from_sql(mut buf: &[u8]) -> Result<i64, StdBox<Error + Sync + Send>> {
+pub fn timestamp_from_sql(mut buf: &[u8]) -> Result<i64, StdBox<dyn Error + Sync + Send>> {
     let v = buf.read_i64::<BigEndian>()?;
     if !buf.is_empty() {
         return Err("invalid message length".into());
@@ -356,7 +356,7 @@ pub fn date_to_sql(v: i32, buf: &mut Vec<u8>) {
 ///
 /// The value represents the number of days since January 1st, 2000.
 #[inline]
-pub fn date_from_sql(mut buf: &[u8]) -> Result<i32, StdBox<Error + Sync + Send>> {
+pub fn date_from_sql(mut buf: &[u8]) -> Result<i32, StdBox<dyn Error + Sync + Send>> {
     let v = buf.read_i32::<BigEndian>()?;
     if !buf.is_empty() {
         return Err("invalid message length".into());
@@ -376,7 +376,7 @@ pub fn time_to_sql(v: i64, buf: &mut Vec<u8>) {
 ///
 /// The value represents the number of microseconds since midnight.
 #[inline]
-pub fn time_from_sql(mut buf: &[u8]) -> Result<i64, StdBox<Error + Sync + Send>> {
+pub fn time_from_sql(mut buf: &[u8]) -> Result<i64, StdBox<dyn Error + Sync + Send>> {
     let v = buf.read_i64::<BigEndian>()?;
     if !buf.is_empty() {
         return Err("invalid message length".into());
@@ -392,7 +392,7 @@ pub fn macaddr_to_sql(v: [u8; 6], buf: &mut Vec<u8>) {
 
 /// Deserializes a `MACADDR` value.
 #[inline]
-pub fn macaddr_from_sql(buf: &[u8]) -> Result<[u8; 6], StdBox<Error + Sync + Send>> {
+pub fn macaddr_from_sql(buf: &[u8]) -> Result<[u8; 6], StdBox<dyn Error + Sync + Send>> {
     if buf.len() != 6 {
         return Err("invalid message length".into());
     }
@@ -409,7 +409,7 @@ pub fn uuid_to_sql(v: [u8; 16], buf: &mut Vec<u8>) {
 
 /// Deserializes a `UUID` value.
 #[inline]
-pub fn uuid_from_sql(buf: &[u8]) -> Result<[u8; 16], StdBox<Error + Sync + Send>> {
+pub fn uuid_from_sql(buf: &[u8]) -> Result<[u8; 16], StdBox<dyn Error + Sync + Send>> {
     if buf.len() != 16 {
         return Err("invalid message length".into());
     }
@@ -426,11 +426,11 @@ pub fn array_to_sql<T, I, J, F>(
     elements: J,
     mut serializer: F,
     buf: &mut Vec<u8>,
-) -> Result<(), StdBox<Error + Sync + Send>>
+) -> Result<(), StdBox<dyn Error + Sync + Send>>
 where
     I: IntoIterator<Item = ArrayDimension>,
     J: IntoIterator<Item = T>,
-    F: FnMut(T, &mut Vec<u8>) -> Result<IsNull, StdBox<Error + Sync + Send>>,
+    F: FnMut(T, &mut Vec<u8>) -> Result<IsNull, StdBox<dyn Error + Sync + Send>>,
 {
     let dimensions_idx = buf.len();
     buf.extend_from_slice(&[0; 4]);
@@ -469,7 +469,7 @@ where
 
 /// Deserializes an array value.
 #[inline]
-pub fn array_from_sql<'a>(mut buf: &'a [u8]) -> Result<Array<'a>, StdBox<Error + Sync + Send>> {
+pub fn array_from_sql<'a>(mut buf: &'a [u8]) -> Result<Array<'a>, StdBox<dyn Error + Sync + Send>> {
     let dimensions = buf.read_i32::<BigEndian>()?;
     if dimensions < 0 {
         return Err("invalid dimension count".into());
@@ -547,10 +547,10 @@ pub struct ArrayDimensions<'a>(&'a [u8]);
 
 impl<'a> FallibleIterator for ArrayDimensions<'a> {
     type Item = ArrayDimension;
-    type Error = StdBox<Error + Sync + Send>;
+    type Error = StdBox<dyn Error + Sync + Send>;
 
     #[inline]
-    fn next(&mut self) -> Result<Option<ArrayDimension>, StdBox<Error + Sync + Send>> {
+    fn next(&mut self) -> Result<Option<ArrayDimension>, StdBox<dyn Error + Sync + Send>> {
         if self.0.is_empty() {
             return Ok(None);
         }
@@ -589,10 +589,10 @@ pub struct ArrayValues<'a> {
 
 impl<'a> FallibleIterator for ArrayValues<'a> {
     type Item = Option<&'a [u8]>;
-    type Error = StdBox<Error + Sync + Send>;
+    type Error = StdBox<dyn Error + Sync + Send>;
 
     #[inline]
-    fn next(&mut self) -> Result<Option<Option<&'a [u8]>>, StdBox<Error + Sync + Send>> {
+    fn next(&mut self) -> Result<Option<Option<&'a [u8]>>, StdBox<dyn Error + Sync + Send>> {
         if self.remaining == 0 {
             if !self.buf.is_empty() {
                 return Err("invalid message length".into());
@@ -634,10 +634,10 @@ pub fn range_to_sql<F, G>(
     lower: F,
     upper: G,
     buf: &mut Vec<u8>,
-) -> Result<(), StdBox<Error + Sync + Send>>
+) -> Result<(), StdBox<dyn Error + Sync + Send>>
 where
-    F: FnOnce(&mut Vec<u8>) -> Result<RangeBound<IsNull>, StdBox<Error + Sync + Send>>,
-    G: FnOnce(&mut Vec<u8>) -> Result<RangeBound<IsNull>, StdBox<Error + Sync + Send>>,
+    F: FnOnce(&mut Vec<u8>) -> Result<RangeBound<IsNull>, StdBox<dyn Error + Sync + Send>>,
+    G: FnOnce(&mut Vec<u8>) -> Result<RangeBound<IsNull>, StdBox<dyn Error + Sync + Send>>,
 {
     let tag_idx = buf.len();
     buf.push(0);
@@ -663,9 +663,9 @@ where
 fn write_bound<F>(
     bound: F,
     buf: &mut Vec<u8>,
-) -> Result<RangeBound<()>, StdBox<Error + Sync + Send>>
+) -> Result<RangeBound<()>, StdBox<dyn Error + Sync + Send>>
 where
-    F: FnOnce(&mut Vec<u8>) -> Result<RangeBound<IsNull>, StdBox<Error + Sync + Send>>,
+    F: FnOnce(&mut Vec<u8>) -> Result<RangeBound<IsNull>, StdBox<dyn Error + Sync + Send>>,
 {
     let base = buf.len();
     buf.extend_from_slice(&[0; 4]);
@@ -702,7 +702,7 @@ pub enum RangeBound<T> {
 
 /// Deserializes a range value.
 #[inline]
-pub fn range_from_sql<'a>(mut buf: &'a [u8]) -> Result<Range<'a>, StdBox<Error + Sync + Send>> {
+pub fn range_from_sql<'a>(mut buf: &'a [u8]) -> Result<Range<'a>, StdBox<dyn Error + Sync + Send>> {
     let tag = buf.read_u8()?;
 
     if tag == RANGE_EMPTY {
@@ -728,7 +728,7 @@ fn read_bound<'a>(
     tag: u8,
     unbounded: u8,
     inclusive: u8,
-) -> Result<RangeBound<Option<&'a [u8]>>, StdBox<Error + Sync + Send>> {
+) -> Result<RangeBound<Option<&'a [u8]>>, StdBox<dyn Error + Sync + Send>> {
     if tag & unbounded != 0 {
         Ok(RangeBound::Unbounded)
     } else {
@@ -770,7 +770,7 @@ pub fn point_to_sql(x: f64, y: f64, buf: &mut Vec<u8>) {
 
 /// Deserializes a point value.
 #[inline]
-pub fn point_from_sql(mut buf: &[u8]) -> Result<Point, StdBox<Error + Sync + Send>> {
+pub fn point_from_sql(mut buf: &[u8]) -> Result<Point, StdBox<dyn Error + Sync + Send>> {
     let x = buf.read_f64::<BigEndian>()?;
     let y = buf.read_f64::<BigEndian>()?;
     if !buf.is_empty() {
@@ -811,7 +811,7 @@ pub fn box_to_sql(x1: f64, y1: f64, x2: f64, y2: f64, buf: &mut Vec<u8>) {
 
 /// Deserializes a box value.
 #[inline]
-pub fn box_from_sql(mut buf: &[u8]) -> Result<Box, StdBox<Error + Sync + Send>> {
+pub fn box_from_sql(mut buf: &[u8]) -> Result<Box, StdBox<dyn Error + Sync + Send>> {
     let x1 = buf.read_f64::<BigEndian>()?;
     let y1 = buf.read_f64::<BigEndian>()?;
     let x2 = buf.read_f64::<BigEndian>()?;
@@ -852,7 +852,7 @@ pub fn path_to_sql<I>(
     closed: bool,
     points: I,
     buf: &mut Vec<u8>,
-) -> Result<(), StdBox<Error + Sync + Send>>
+) -> Result<(), StdBox<dyn Error + Sync + Send>>
 where
     I: IntoIterator<Item = (f64, f64)>,
 {
@@ -875,7 +875,7 @@ where
 
 /// Deserializes a Postgres path.
 #[inline]
-pub fn path_from_sql<'a>(mut buf: &'a [u8]) -> Result<Path<'a>, StdBox<Error + Sync + Send>> {
+pub fn path_from_sql<'a>(mut buf: &'a [u8]) -> Result<Path<'a>, StdBox<dyn Error + Sync + Send>> {
     let closed = buf.read_u8()? != 0;
     let points = buf.read_i32::<BigEndian>()?;
 
@@ -918,10 +918,10 @@ pub struct PathPoints<'a> {
 
 impl<'a> FallibleIterator for PathPoints<'a> {
     type Item = Point;
-    type Error = StdBox<Error + Sync + Send>;
+    type Error = StdBox<dyn Error + Sync + Send>;
 
     #[inline]
-    fn next(&mut self) -> Result<Option<Point>, StdBox<Error + Sync + Send>> {
+    fn next(&mut self) -> Result<Option<Point>, StdBox<dyn Error + Sync + Send>> {
         if self.remaining == 0 {
             if !self.buf.is_empty() {
                 return Err("invalid message length".into());
@@ -949,7 +949,7 @@ mod test {
     use std::collections::HashMap;
 
     use super::*;
-    use IsNull;
+    use crate::IsNull;
 
     #[test]
     fn bool() {