diff --git a/flake.lock b/flake.lock
index aae8aa6..4b129f7 100644
--- a/flake.lock
+++ b/flake.lock
@@ -2,12 +2,12 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1721379653,
-        "narHash": "sha256-8MUgifkJ7lkZs3u99UDZMB4kbOxvMEXQZ31FO3SopZ0=",
-        "rev": "1d9c2c9b3e71b9ee663d11c5d298727dace8d374",
-        "revCount": 655136,
+        "lastModified": 1722813957,
+        "narHash": "sha256-IAoYyYnED7P8zrBFMnmp7ydaJfwTnwcnqxUElC1I26Y=",
+        "rev": "cb9a96f23c491c081b38eab96d22fa958043c9fa",
+        "revCount": 662544,
         "type": "tarball",
-        "url": "https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.1.655136%2Brev-1d9c2c9b3e71b9ee663d11c5d298727dace8d374/0190cd4f-c0eb-72cb-834b-ac854aa282dc/source.tar.gz"
+        "url": "https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.1.662544%2Brev-cb9a96f23c491c081b38eab96d22fa958043c9fa/0191261c-f106-7d9e-a0c0-f57924d24f7d/source.tar.gz"
       },
       "original": {
         "type": "tarball",
@@ -27,11 +27,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1721355572,
-        "narHash": "sha256-I4TQ2guV9jTmZsXeWt5HMojcaqNZHII4zu0xIKZEovM=",
+        "lastModified": 1723170066,
+        "narHash": "sha256-SFkQfOA+8AIYJsPlQtxNP+z5jRLfz91z/aOrV94pPmw=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "d5bc7b1b21cf937fb8ff108ae006f6776bdb163d",
+        "rev": "fecfe4d7c96fea2982c7907997b387a6b52c1093",
         "type": "github"
       },
       "original": {
diff --git a/src/app/formats.rs b/src/app/formats.rs
index 1e8b43f..09949c4 100644
--- a/src/app/formats.rs
+++ b/src/app/formats.rs
@@ -121,6 +121,9 @@ fn read_mp3<P: AsRef<Path>>(path: P) -> Result<SongMetadata, Error> {
 }
 
 mod ape_ext {
+	use regex::Regex;
+	use std::sync::LazyLock;
+
 	pub fn read_string(item: &ape::Item) -> Option<String> {
 		match item.value {
 			ape::ItemValue::Text(ref s) => Some(s.clone()),
@@ -139,11 +142,12 @@ mod ape_ext {
 		}
 	}
 
+	static X_OF_Y_REGEX: LazyLock<Regex> = LazyLock::new(|| Regex::new(r#"^\d+"#).unwrap());
+
 	pub fn read_x_of_y(item: &ape::Item) -> Option<u32> {
 		match item.value {
 			ape::ItemValue::Text(ref s) => {
-				let format = regex::Regex::new(r#"^\d+"#).unwrap();
-				if let Some(m) = format.find(s) {
+				if let Some(m) = X_OF_Y_REGEX.find(s) {
 					s[m.start()..m.end()].parse().ok()
 				} else {
 					None