diff --git a/clippy_dev/Cargo.toml b/clippy_dev/Cargo.toml
index d6057ba97..5380ecd98 100644
--- a/clippy_dev/Cargo.toml
+++ b/clippy_dev/Cargo.toml
@@ -9,3 +9,4 @@ clap = "~2.32"
 itertools = "0.7"
 regex = "1"
 lazy_static = "1.0"
+walkdir = "2"
diff --git a/clippy_dev/src/lib.rs b/clippy_dev/src/lib.rs
index eee9089e7..8477183ae 100644
--- a/clippy_dev/src/lib.rs
+++ b/clippy_dev/src/lib.rs
@@ -14,6 +14,7 @@
 use itertools::Itertools;
 use lazy_static::lazy_static;
 use regex::Regex;
+use walkdir::WalkDir;
 use std::collections::HashMap;
 use std::ffi::OsStr;
 use std::fs;
@@ -35,6 +36,7 @@ lazy_static! {
     pub static ref DOCS_LINK: String = "https://rust-lang-nursery.github.io/rust-clippy/master/index.html".to_string();
 }
 
+/// Lint data parsed from the Clippy source code.
 #[derive(Clone, PartialEq, Debug)]
 pub struct Lint {
     pub name: String,
@@ -66,11 +68,12 @@ impl Lint {
     }
 }
 
+/// Gathers all files in `src/clippy_lints` and gathers all lints inside
 pub fn gather_all() -> impl Iterator<Item=Lint> {
     lint_files().flat_map(|f| gather_from_file(&f))
 }
 
-fn gather_from_file(dir_entry: &fs::DirEntry) -> impl Iterator<Item=Lint> {
+fn gather_from_file(dir_entry: &walkdir::DirEntry) -> impl Iterator<Item=Lint> {
     let mut file = fs::File::open(dir_entry.path()).unwrap();
     let mut content = String::new();
     file.read_to_string(&mut content).unwrap();
@@ -89,9 +92,11 @@ fn parse_contents(content: &str, filename: &str) -> impl Iterator<Item=Lint> {
 }
 
 /// Collects all .rs files in the `clippy_lints/src` directory
-fn lint_files() -> impl Iterator<Item=fs::DirEntry> {
-    fs::read_dir("../clippy_lints/src")
-        .unwrap()
+fn lint_files() -> impl Iterator<Item=walkdir::DirEntry> {
+    // We use `WalkDir` instead of `fs::read_dir` here in order to recurse into subdirectories.
+    // Otherwise we would not collect all the lints, for example in `clippy_lints/src/methods/`.
+    WalkDir::new("../clippy_lints/src")
+        .into_iter()
         .filter_map(|f| f.ok())
         .filter(|f| f.path().extension() == Some(OsStr::new("rs")))
 }
diff --git a/clippy_dev/src/main.rs b/clippy_dev/src/main.rs
index d1161323b..9e78def78 100644
--- a/clippy_dev/src/main.rs
+++ b/clippy_dev/src/main.rs
@@ -44,7 +44,7 @@ fn print_lints() {
         if lint_group == "Deprecated" { continue; }
         println!("\n## {}", lint_group);
 
-        lints.sort_by(|a, b| a.name.cmp(&b.name));
+        lints.sort_by_key(|l| l.name.clone());
 
         for lint in lints {
             println!("* [{}]({}#{}) ({})", lint.name, clippy_dev::DOCS_LINK.clone(), lint.name, lint.desc);