diff --git a/Cargo.toml b/Cargo.toml
index 869bc8bd1..046478773 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -28,6 +28,9 @@ bitflags = "2.4.0"
 errno = "0.2.8"
 lazy_static = "1.4.0"
 libc = "0.2.137"
+# lru pulls in hashbrown by default, which uses a faster (though less DoS resistant) hashing algo.
+# disabling default features uses the stdlib instead, but it doubles the time to rewrite the history
+# files as of 22 April 2024.
 lru = "0.10.0"
 nix = { version = "0.25.0", default-features = false, features = ["inotify", "resource", "fs"] }
 num-traits = "0.2.15"