diff --git a/Cargo.lock b/Cargo.lock
index 8129936..8745bf4 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -495,6 +495,12 @@ version = "0.7.4"
 source = "registry+/~https://github.com/rust-lang/crates.io-index"
 checksum = "e5ea92a5b6195c6ef2a0295ea818b312502c6fc94dde986c5553242e18fd4ce2"
 
+[[package]]
+name = "rustc-hash"
+version = "2.0.0"
+source = "registry+/~https://github.com/rust-lang/crates.io-index"
+checksum = "583034fd73374156e66797ed8e5b0d5690409c9226b22d87cb7f19821c05d152"
+
 [[package]]
 name = "rustdoc-types"
 version = "0.25.0"
@@ -641,6 +647,7 @@ dependencies = [
  "itertools 0.12.1",
  "maplit",
  "rayon",
+ "rustc-hash",
  "rustdoc-types",
  "serde",
  "serde_json",
diff --git a/Cargo.toml b/Cargo.toml
index 635d631..f596091 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,6 +14,7 @@ readme = "./README.md"
 trustfall = "0.7.1"
 rustdoc-types = "0.25.0"
 rayon = { version = "1.10.0", optional = true }
+rustc-hash = { version = "2.0.0", optional = true }
 
 [features]
 default = []
@@ -21,6 +22,8 @@ default = []
 # performance on big crates, but may impact performance on small crates and
 # definitely increases the memory usage
 rayon = ["dep:rayon"]
+# Use rustc-hash::{FxHashMap, FxHashSet} internally for improved performance
+rustc-hash = ["dep:rustc-hash"]
 
 [[bench]]
 name = "indexed_crate"
diff --git a/src/visibility_tracker.rs b/src/visibility_tracker.rs
index 8670905..9b102d4 100644
--- a/src/visibility_tracker.rs
+++ b/src/visibility_tracker.rs
@@ -1,3 +1,6 @@
+#[cfg(feature = "rustc-hash")]
+use rustc_hash::{FxHashMap as HashMap, FxHashSet as HashSet};
+#[cfg(not(feature = "rustc-hash"))]
 use std::collections::{HashMap, HashSet};
 
 use rustdoc_types::{Crate, GenericArgs, Id, Item, ItemEnum, TypeAlias, Visibility};