diff --git a/clippy_dev/src/fmt.rs b/clippy_dev/src/fmt.rs
index 2b2138d3108d..781e37e6144e 100644
--- a/clippy_dev/src/fmt.rs
+++ b/clippy_dev/src/fmt.rs
@@ -268,7 +268,7 @@ fn run_rustfmt(update_mode: UpdateMode) {
     .expect("invalid rustfmt path");
     rustfmt_path.truncate(rustfmt_path.trim_end().len());
 
-    let args: Vec<_> = walk_dir_no_dot_or_target()
+    let args: Vec<_> = walk_dir_no_dot_or_target(".")
         .filter_map(|e| {
             let e = expect_action(e, ErrAction::Read, ".");
             e.path()
diff --git a/clippy_dev/src/parse.rs b/clippy_dev/src/parse.rs
index 5c89f83dbd6a..f151a3c8fee9 100644
--- a/clippy_dev/src/parse.rs
+++ b/clippy_dev/src/parse.rs
@@ -1,11 +1,10 @@
 pub mod cursor;
 
 use self::cursor::{Capture, Cursor};
-use crate::utils::{ErrAction, File, Scoped, expect_action};
+use crate::utils::{ErrAction, File, Scoped, expect_action, walk_dir_no_dot_or_target};
 use core::range::Range;
 use std::fs;
-use std::path::{Path, PathBuf};
-use walkdir::{DirEntry, WalkDir};
+use std::path::{self, Path, PathBuf};
 
 pub struct ParseCxImpl;
 pub type ParseCx<'cx> = &'cx mut ParseCxImpl;
@@ -43,18 +42,38 @@ impl ParseCxImpl {
         let mut contents = String::new();
         for e in expect_action(fs::read_dir("."), ErrAction::Read, ".") {
             let e = expect_action(e, ErrAction::Read, ".");
-            if !expect_action(e.file_type(), ErrAction::Read, ".").is_dir() {
-                continue;
-            }
-            let Ok(mut name) = e.file_name().into_string() else {
+
+            // Skip if this isn't a lint crate's directory.
+            let mut crate_path = if expect_action(e.file_type(), ErrAction::Read, ".").is_dir()
+                && let Ok(crate_path) = e.file_name().into_string()
+                && crate_path.starts_with("clippy_lints")
+                && crate_path != "clippy_lints_internal"
+            {
+                crate_path
+            } else {
                 continue;
             };
-            if name.starts_with("clippy_lints") && name != "clippy_lints_internal" {
-                name.push_str("/src");
-                for (file, module) in read_src_with_module(name.as_ref()) {
+
+            crate_path.push(path::MAIN_SEPARATOR);
+            crate_path.push_str("src");
+            for e in walk_dir_no_dot_or_target(&crate_path) {
+                let e = expect_action(e, ErrAction::Read, &crate_path);
+                if let Some(path) = e.path().to_str()
+                    && let Some(path) = path.strip_suffix(".rs")
+                    && let Some(path) = path.get(crate_path.len() + 1..)
+                {
+                    let module = if path == "lib" {
+                        String::new()
+                    } else {
+                        let path = path
+                            .strip_suffix("mod")
+                            .and_then(|x| x.strip_suffix(path::MAIN_SEPARATOR))
+                            .unwrap_or(path);
+                        path.replace(['/', '\\'], "::")
+                    };
                     parse_clippy_lint_decls(
-                        file.path(),
-                        File::open_read_to_cleared_string(file.path(), &mut contents),
+                        e.path(),
+                        File::open_read_to_cleared_string(e.path(), &mut contents),
                         &module,
                         &mut lints,
                     );
@@ -132,37 +151,6 @@ impl ParseCxImpl {
     }
 }
 
-/// Reads the source files from the given root directory
-fn read_src_with_module(src_root: &Path) -> impl use<'_> + Iterator<Item = (DirEntry, String)> {
-    WalkDir::new(src_root).into_iter().filter_map(move |e| {
-        let e = expect_action(e, ErrAction::Read, src_root);
-        let path = e.path().as_os_str().as_encoded_bytes();
-        if let Some(path) = path.strip_suffix(b".rs")
-            && let Some(path) = path.get(src_root.as_os_str().len() + 1..)
-        {
-            if path == b"lib" {
-                Some((e, String::new()))
-            } else {
-                let path = if let Some(path) = path.strip_suffix(b"mod")
-                    && let Some(path) = path.strip_suffix(b"/").or_else(|| path.strip_suffix(b"\\"))
-                {
-                    path
-                } else {
-                    path
-                };
-                if let Ok(path) = str::from_utf8(path) {
-                    let path = path.replace(['/', '\\'], "::");
-                    Some((e, path))
-                } else {
-                    None
-                }
-            }
-        } else {
-            None
-        }
-    })
-}
-
 /// Parse a source file looking for `declare_clippy_lint` macro invocations.
 fn parse_clippy_lint_decls(path: &Path, contents: &str, module: &str, lints: &mut Vec<Lint>) {
     #[allow(clippy::enum_glob_use)]
diff --git a/clippy_dev/src/rename_lint.rs b/clippy_dev/src/rename_lint.rs
index 04942cd639d6..bbe5baa41cce 100644
--- a/clippy_dev/src/rename_lint.rs
+++ b/clippy_dev/src/rename_lint.rs
@@ -127,7 +127,7 @@ pub fn rename<'cx>(cx: ParseCx<'cx>, clippy_version: Version, old_name: &'cx str
     }
 
     let mut update_fn = file_update_fn(old_name, new_name, mod_edit);
-    for e in walk_dir_no_dot_or_target() {
+    for e in walk_dir_no_dot_or_target(".") {
         let e = expect_action(e, ErrAction::Read, ".");
         if e.path().as_os_str().as_encoded_bytes().ends_with(b".rs") {
             updater.update_file(e.path(), &mut update_fn);
diff --git a/clippy_dev/src/utils.rs b/clippy_dev/src/utils.rs
index c01b05ec1720..52452dd86b49 100644
--- a/clippy_dev/src/utils.rs
+++ b/clippy_dev/src/utils.rs
@@ -593,8 +593,8 @@ pub fn delete_dir_if_exists(path: &Path) {
 }
 
 /// Walks all items excluding top-level dot files/directories and any target directories.
-pub fn walk_dir_no_dot_or_target() -> impl Iterator<Item = ::walkdir::Result<::walkdir::DirEntry>> {
-    WalkDir::new(".").into_iter().filter_entry(|e| {
+pub fn walk_dir_no_dot_or_target(p: impl AsRef<Path>) -> impl Iterator<Item = ::walkdir::Result<::walkdir::DirEntry>> {
+    WalkDir::new(p).into_iter().filter_entry(|e| {
         e.path()
             .file_name()
             .is_none_or(|x| x != "target" && x.as_encoded_bytes().first().copied() != Some(b'.'))