diff --git a/parser/Cargo.toml b/parser/Cargo.toml
index 7bc449a..aac5d4a 100644
--- a/parser/Cargo.toml
+++ b/parser/Cargo.toml
@@ -8,9 +8,10 @@ license = "MIT/Apache-2.0"
 description = "The missing YAML 1.2 parser for rust"
 repository = "https://github.com/chyh1990/yaml-rust"
 readme = "README.md"
+edition = "2018"
 
 [dependencies]
 linked-hash-map = ">=0.0.9, <0.6"
 
 [dev-dependencies]
-quickcheck = "0.7"
+quickcheck = "0.9"
diff --git a/parser/src/emitter.rs b/parser/src/emitter.rs
index 872d1c8..ab589a3 100644
--- a/parser/src/emitter.rs
+++ b/parser/src/emitter.rs
@@ -1,7 +1,7 @@
 use std::convert::From;
 use std::error::Error;
 use std::fmt::{self, Display};
-use yaml::{Hash, Yaml};
+use crate::yaml::{Hash, Yaml};
 
 #[derive(Copy, Clone, Debug)]
 pub enum EmitError {
@@ -10,14 +10,7 @@ pub enum EmitError {
 }
 
 impl Error for EmitError {
-    fn description(&self) -> &str {
-        match *self {
-            EmitError::FmtError(ref err) => err.description(),
-            EmitError::BadHashmapKey => "bad hashmap key",
-        }
-    }
-
-    fn cause(&self) -> Option<&Error> {
+    fn cause(&self) -> Option<&dyn Error> {
         None
     }
 }
@@ -38,7 +31,7 @@ impl From<fmt::Error> for EmitError {
 }
 
 pub struct YamlEmitter<'a> {
-    writer: &'a mut fmt::Write,
+    writer: &'a mut dyn fmt::Write,
     best_indent: usize,
     compact: bool,
 
@@ -48,7 +41,7 @@ pub struct YamlEmitter<'a> {
 pub type EmitResult = Result<(), EmitError>;
 
 // from serialize::json
-fn escape_str(wr: &mut fmt::Write, v: &str) -> Result<(), fmt::Error> {
+fn escape_str(wr: &mut dyn fmt::Write, v: &str) -> Result<(), fmt::Error> {
     wr.write_str("\"")?;
 
     let mut start = 0;
@@ -111,7 +104,7 @@ fn escape_str(wr: &mut fmt::Write, v: &str) -> Result<(), fmt::Error> {
 }
 
 impl<'a> YamlEmitter<'a> {
-    pub fn new(writer: &'a mut fmt::Write) -> YamlEmitter {
+    pub fn new(writer: &'a mut dyn fmt::Write) -> YamlEmitter {
         YamlEmitter {
             writer,
             best_indent: 2,
@@ -316,12 +309,12 @@ fn need_quotes(string: &str) -> bool {
             | '\"'
             | '\''
             | '\\'
-            | '\0'...'\x06'
+            | '\0'..='\x06'
             | '\t'
             | '\n'
             | '\r'
-            | '\x0e'...'\x1a'
-            | '\x1c'...'\x1f' => true,
+            | '\x0e'..='\x1a'
+            | '\x1c'..='\x1f' => true,
             _ => false,
         })
         || [
@@ -344,7 +337,7 @@ fn need_quotes(string: &str) -> bool {
 #[cfg(test)]
 mod test {
     use super::*;
-    use YamlLoader;
+    use crate::YamlLoader;
 
     #[test]
     fn test_emit_simple() {
diff --git a/parser/src/lib.rs b/parser/src/lib.rs
index 40cff18..af1423c 100644
--- a/parser/src/lib.rs
+++ b/parser/src/lib.rs
@@ -52,10 +52,10 @@ pub mod scanner;
 pub mod yaml;
 
 // reexport key APIs
-pub use emitter::{EmitError, YamlEmitter};
-pub use parser::Event;
-pub use scanner::ScanError;
-pub use yaml::{Yaml, YamlLoader};
+pub use crate::emitter::{EmitError, YamlEmitter};
+pub use crate::parser::Event;
+pub use crate::scanner::ScanError;
+pub use crate::yaml::{Yaml, YamlLoader};
 
 #[cfg(test)]
 mod tests {
diff --git a/parser/src/parser.rs b/parser/src/parser.rs
index 22692ff..cf25fdd 100644
--- a/parser/src/parser.rs
+++ b/parser/src/parser.rs
@@ -1,4 +1,4 @@
-use scanner::*;
+use crate::scanner::*;
 use std::collections::HashMap;
 
 #[derive(Clone, Copy, PartialEq, Debug, Eq)]
diff --git a/parser/src/scanner.rs b/parser/src/scanner.rs
index 6f4fa58..b2ce148 100644
--- a/parser/src/scanner.rs
+++ b/parser/src/scanner.rs
@@ -67,7 +67,7 @@ impl Error for ScanError {
         self.info.as_ref()
     }
 
-    fn cause(&self) -> Option<&Error> {
+    fn cause(&self) -> Option<&dyn Error> {
         None
     }
 }
@@ -199,7 +199,7 @@ fn is_digit(c: char) -> bool {
 #[inline]
 fn is_alpha(c: char) -> bool {
     match c {
-        '0'...'9' | 'a'...'z' | 'A'...'Z' => true,
+        '0'..='9' | 'a'..='z' | 'A'..='Z' => true,
         '_' | '-' => true,
         _ => false,
     }
@@ -211,9 +211,9 @@ fn is_hex(c: char) -> bool {
 #[inline]
 fn as_hex(c: char) -> u32 {
     match c {
-        '0'...'9' => (c as u32) - ('0' as u32),
-        'a'...'f' => (c as u32) - ('a' as u32) + 10,
-        'A'...'F' => (c as u32) - ('A' as u32) + 10,
+        '0'..='9' => (c as u32) - ('0' as u32),
+        'a'..='f' => (c as u32) - ('a' as u32) + 10,
+        'A'..='F' => (c as u32) - ('A' as u32) + 10,
         _ => unreachable!(),
     }
 }
diff --git a/parser/src/yaml.rs b/parser/src/yaml.rs
index fe112cc..f529f38 100644
--- a/parser/src/yaml.rs
+++ b/parser/src/yaml.rs
@@ -1,6 +1,6 @@
 use linked_hash_map::LinkedHashMap;
-use parser::*;
-use scanner::{Marker, ScanError, TScalarStyle, TokenType};
+use crate::parser::*;
+use crate::scanner::{Marker, ScanError, TScalarStyle, TokenType};
 use std::collections::BTreeMap;
 use std::f64;
 use std::i64;
@@ -368,7 +368,7 @@ impl Iterator for YamlIter {
 #[cfg(test)]
 mod test {
     use std::f64;
-    use yaml::*;
+    use crate::yaml::*;
     #[test]
     fn test_coerce() {
         let s = "---
diff --git a/parser/tests/quickcheck.rs b/parser/tests/quickcheck.rs
index c2c89bc..0efd679 100644
--- a/parser/tests/quickcheck.rs
+++ b/parser/tests/quickcheck.rs
@@ -3,7 +3,6 @@ extern crate yaml_rust;
 extern crate quickcheck;
 
 use quickcheck::TestResult;
-use std::error::Error;
 use yaml_rust::{Yaml, YamlEmitter, YamlLoader};
 
 quickcheck! {
@@ -16,7 +15,7 @@ quickcheck! {
         }
         match YamlLoader::load_from_str(&out_str) {
             Ok(output) => TestResult::from_bool(output.len() == 1 && input == output[0]),
-            Err(err) => TestResult::error(err.description()),
+            Err(err) => TestResult::error(err.to_string()),
         }
     }
 }