diff --git a/Cargo.toml b/Cargo.toml
index 9bdb48b6..641672ae 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -34,7 +34,7 @@ derive = ["dep:narrow-derive"]
 unsafe = []
 
 [dependencies]
-narrow-derive = { path = "narrow-derive", optional = true }
+narrow-derive = { path = "narrow-derive", version = "0.2.0", optional = true }
 
 [dev-dependencies]
 criterion = { version = "0.5", default-features = false }
diff --git a/src/buffer.rs b/src/buffer.rs
index da114df4..86b1ae73 100644
--- a/src/buffer.rs
+++ b/src/buffer.rs
@@ -18,17 +18,6 @@ pub trait BufferType {
     type Buffer<T: FixedSize>: Buffer<T>;
 }
 
-// pub trait ValidityBuffer: BufferType {
-//     type Validity<'a, T: FixedSize + 'a, const NULLABLE: bool>: Buffer<T>
-//         + crate::validity::Validity<NULLABLE>;
-// }
-// impl<U> ValidityBuffer for U
-// where
-//     U: BufferType,
-// {
-//     type Validity<'a, T: FixedSize + 'a, const NULLABLE: bool> = Self::Buffer<'a, T>;
-// }
-
 /// An immutable reference to a buffer.
 ///
 /// This can be used to provide immutable access to an internal buffer.