diff --git a/Cargo.lock b/Cargo.lock
index 2b3381ce..0bccda26 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -311,6 +311,7 @@ dependencies = [
  "portable-atomic",
  "rayon",
  "regex",
+ "rustc-hash",
  "serde",
  "serde_json",
  "stfu8",
@@ -707,6 +708,12 @@ version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "323c417e1d9665a65b263ec744ba09030cfb277e9daa0b018a4ab62e57bc8189"
 
+[[package]]
+name = "rustc-hash"
+version = "2.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94300abf3f1ae2e2b8ffb7b58043de3d399c73fa6f4b73826402a5c457614dbe"
+
 [[package]]
 name = "rustix"
 version = "1.1.4"
diff --git a/Cargo.toml b/Cargo.toml
index 8bb0cf50..cdd55995 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -42,6 +42,7 @@ serde_json = "1.0"
 sysinfo = "0.39"
 ctrlc = "3"
 chrono = "0.4"
+rustc-hash = "2"
 
 [target.'cfg(not(target_has_atomic = "64"))'.dependencies]
 portable-atomic = "1.4"
diff --git a/src/dir_walker.rs b/src/dir_walker.rs
index 11d331b2..c245d6ad 100644
--- a/src/dir_walker.rs
+++ b/src/dir_walker.rs
@@ -20,6 +20,8 @@ use std::path::PathBuf;
 
 use std::collections::HashSet;
 
+use rustc_hash::FxHashSet;
+
 use crate::node::build_node;
 use std::fs::DirEntry;
 
@@ -68,7 +70,10 @@ struct PendingDir {
 }
 
 pub fn walk_it(dirs: HashSet<PathBuf>, walk_data: &WalkData) -> Vec<Node> {
-    let mut inodes = HashSet::new();
+    // FxHash is substantially faster than std's default SipHash on small
+    // primitive keys. DoS resistance is irrelevant here; the keys are
+    // (inode, device) pairs from the filesystem, not user input.
+    let mut inodes: FxHashSet<(u64, u64)> = FxHashSet::default();
     let mut top_level_nodes: Vec<Node> = Vec::new();
 
     for d in dirs {
@@ -126,7 +131,7 @@ pub fn walk_it(dirs: HashSet<PathBuf>, walk_data: &WalkData) -> Vec<Node> {
 }
 
 // Remove files which have the same inode, we don't want to double count them.
-fn clean_inodes(x: Node, inodes: &mut HashSet<(u64, u64)>, walk_data: &WalkData) -> Option<Node> {
+fn clean_inodes(x: Node, inodes: &mut FxHashSet<(u64, u64)>, walk_data: &WalkData) -> Option<Node> {
     if !walk_data.use_apparent_size
         && let Some(id) = x.inode_device
         && !inodes.insert(id)
@@ -522,7 +527,7 @@ mod tests {
     #[test]
     #[allow(clippy::redundant_clone)]
     fn test_should_ignore_file() {
-        let mut inodes = HashSet::new();
+        let mut inodes = FxHashSet::default();
         let n = create_node();
         let walkdata = create_walker(false);
 
@@ -539,7 +544,7 @@ mod tests {
     #[test]
     #[allow(clippy::redundant_clone)]
     fn test_should_not_ignore_files_if_using_apparent_size() {
-        let mut inodes = HashSet::new();
+        let mut inodes = FxHashSet::default();
         let n = create_node();
         let walkdata = create_walker(true);