diff --git a/Cargo.toml b/Cargo.toml
index b895894..a5991f6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,6 +2,7 @@
 name = "fingertips"
 version = "0.1.0"
 authors = ["Jason Orendorff <jason.orendorff@gmail.com>"]
+edition = "2018"
 
 [dependencies]
 argparse = "0.2.1"
diff --git a/src/main.rs b/src/main.rs
index eec7757..ab45791 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -13,16 +13,12 @@
 /// The `main` function at the end handles command-line arguments. It calls one
 /// of the two functions above to do the work.
 
-extern crate argparse;
-extern crate byteorder;
-
 mod index;
 mod read;
 mod write;
 mod merge;
 mod tmp;
 
-use std::error::Error;
 use std::fs::File;
 use std::io;
 use std::io::prelude::*;
@@ -31,10 +27,10 @@ use std::sync::mpsc::{channel, Receiver};
 use std::thread::{spawn, JoinHandle};
 use argparse::{ArgumentParser, StoreTrue, Collect};
 
-use index::InMemoryIndex;
-use write::write_index_to_tmp_file;
-use merge::FileMerge;
-use tmp::TmpDir;
+use crate::index::InMemoryIndex;
+use crate::write::write_index_to_tmp_file;
+use crate::merge::FileMerge;
+use crate::tmp::TmpDir;
 
 /// Create an inverted index for the given list of `documents`,
 /// storing it in the specified `output_dir`.
@@ -298,6 +294,6 @@ fn main() {
 
     match run(filenames, single_threaded) {
         Ok(()) => {}
-        Err(err) => println!("error: {:?}", err.description())
+        Err(err) => println!("error: {}", err)
     }
 }
diff --git a/src/merge.rs b/src/merge.rs
index 038dfc5..2a1adc7 100644
--- a/src/merge.rs
+++ b/src/merge.rs
@@ -3,9 +3,9 @@ use std::io::{self, BufWriter};
 use std::mem;
 use std::path::{Path, PathBuf};
 
-use tmp::TmpDir;
-use read::IndexFileReader;
-use write::IndexFileWriter;
+use crate::tmp::TmpDir;
+use crate::read::IndexFileReader;
+use crate::write::IndexFileWriter;
 
 pub struct FileMerge {
     output_dir: PathBuf,
diff --git a/src/read.rs b/src/read.rs
index 30f50df..460a797 100644
--- a/src/read.rs
+++ b/src/read.rs
@@ -6,7 +6,7 @@ use std::io::prelude::*;
 use std::io::{self, BufReader, SeekFrom};
 use std::path::Path;
 use byteorder::{LittleEndian, ReadBytesExt};
-use write::IndexFileWriter;
+use crate::write::IndexFileWriter;
 
 /// A `IndexFileReader` does a single linear pass over an index file from
 /// beginning to end. Needless to say, this is not how an index is normally
diff --git a/src/tmp.rs b/src/tmp.rs
index 443eeb4..54d4b97 100644
--- a/src/tmp.rs
+++ b/src/tmp.rs
@@ -17,7 +17,7 @@ impl TmpDir {
     }
 
     pub fn create(&mut self) -> io::Result<(PathBuf, BufWriter<File>)> {
-        let mut try = 1;
+        let mut r#try = 1;
         loop {
             let filename = self.dir.join(PathBuf::from(format!("tmp{:08x}.dat", self.n)));
             self.n += 1;
@@ -29,13 +29,13 @@ impl TmpDir {
                 Ok(f) =>
                     return Ok((filename, BufWriter::new(f))),
                 Err(exc) =>
-                    if try < 999 && exc.kind() == io::ErrorKind::AlreadyExists {
+                    if r#try < 999 && exc.kind() == io::ErrorKind::AlreadyExists {
                         // keep going
                     } else {
                         return Err(exc);
                     }
             }
-            try += 1;
+            r#try += 1;
         }
     }
 }
diff --git a/src/write.rs b/src/write.rs
index ee30c60..b42f384 100644
--- a/src/write.rs
+++ b/src/write.rs
@@ -2,8 +2,8 @@ use std::fs::File;
 use std::io::{self, BufWriter, SeekFrom};
 use std::io::prelude::*;
 use std::path::PathBuf;
-use index::InMemoryIndex;
-use tmp::TmpDir;
+use crate::index::InMemoryIndex;
+use crate::tmp::TmpDir;
 use byteorder::{LittleEndian, WriteBytesExt};
 
 /// Writer for saving an index to a binary file.