diff --git a/CHANGELOG.md b/CHANGELOG.md
index 72580d5b7c..8c42dd51ec 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - `bytes::BufMut` is now implemented on `VecInner`.
 - Removed generic from `history_buf::OldestOrdered`.
+- Made `LenType` opt-in.
 
 ### Fixed
 
@@ -19,6 +20,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Removed
 
 - Removed invalid `bytes::Buf` implementation.
+- Removed `DefaultLenType` struct.
 
 ## [v0.9.0] - 2025-04-28 [YANKED]
 
diff --git a/src/c_string.rs b/src/c_string.rs
index ee480a48b4..25df69b7ca 100644
--- a/src/c_string.rs
+++ b/src/c_string.rs
@@ -1,6 +1,6 @@
 //! A fixed capacity [`CString`](https://doc.rust-lang.org/std/ffi/struct.CString.html).
 
-use crate::{len_type::DefaultLenType, vec::Vec, CapacityError, LenType};
+use crate::{vec::Vec, CapacityError, LenType};
 use core::{
     borrow::Borrow,
     cmp::Ordering,
@@ -14,7 +14,7 @@ use core::{
 ///
 /// It stores up to `N - 1` non-nul characters with a trailing nul terminator.
 #[derive(Clone, Hash)]
-pub struct CString<const N: usize, LenT: LenType = DefaultLenType<N>> {
+pub struct CString<const N: usize, LenT: LenType = usize> {
     inner: Vec<u8, N, LenT>,
 }
 
diff --git a/src/len_type.rs b/src/len_type.rs
index 854dbddda6..d42a659d9a 100644
--- a/src/len_type.rs
+++ b/src/len_type.rs
@@ -85,186 +85,6 @@ impl_lentype!(
     usize
 );
 
-macro_rules! impl_lentodefault {
-    ($LenT:ty: $($len:literal),*) => {$(
-        impl SmallestLenType for Const<$len> {
-            type Type = $LenT;
-        }
-    )*};
-}
-
-/// A struct to create individual types for mapping with [`SmallestLenType`].
-///
-/// See the documentation of [`DefaultLenType`] for a detailed explanation.
-pub struct Const<const N: usize>;
-
-/// A trait to map [`Const`] to it's respective [`LenType`].
-///
-/// See the documentation of [`DefaultLenType`] for a detailed explanation.
-#[diagnostic::on_unimplemented(
-    message = "Length `N` does not have a default `LenType` mapping",
-    note = "Provide the `LenType` explicitly, such as `usize`"
-)]
-pub trait SmallestLenType {
-    type Type: LenType;
-}
-
-/// A type alias to perform the `const N: usize` -> `LenType` mapping.
-///
-/// This is impossible to perform directly, but it is possible to write a `const N: usize` -> related `Type` mapping via a const generic argument,
-/// then map from that to an unrelated type via a trait with associated types.
-///
-/// [`Const`] is the "related type" in the above explaination, [`SmallestLenType`] is the mapping trait.
-#[allow(rustdoc::private_intra_doc_links)] // Only publically exposed via `crate::_export`
-pub type DefaultLenType<const N: usize> = <Const<N> as SmallestLenType>::Type;
-
-impl_lentodefault!(ZeroLenType: 0);
-impl_lentodefault!(u8: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255);
-impl_lentodefault!(u16: 256, 300, 400, 500, 512, 600, 700, 800, 900, 1000, 1024, 2000, 2048, 4000, 4096, 8000, 8192, 16000, 16384, 32000, 32768, 65000, 65535);
-#[cfg(any(target_pointer_width = "32", target_pointer_width = "64"))]
-impl_lentodefault!(u32: 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 67108864, 134217728, 268435456, 536870912, 1073741824, 2147483648);
-
 pub const fn check_capacity_fits<LenT: LenType, const N: usize>() {
     assert!(LenT::MAX_USIZE >= N, "The capacity is larger than `LenT` can hold, increase the size of `LenT` or reduce the capacity");
 }
-
-/// Container with 0 capacity always has length 0, so there is no need to track length of such containers at all.
-///
-/// This type is used as a placeholder for length of container with 0 capacity. It allows optimizing total size of
-/// containers like this to 0 bytes.
-///
-/// Logically, this type always stores value 0. Because of this ZeroLenType::one() panics and should never be called.
-#[doc(hidden)]
-#[derive(Copy, Clone, PartialEq, PartialOrd)]
-pub struct ZeroLenType;
-
-impl Debug for ZeroLenType {
-    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-        write!(f, "0")
-    }
-}
-
-impl Display for ZeroLenType {
-    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-        write!(f, "0")
-    }
-}
-
-impl Sealed for ZeroLenType {
-    const ZERO: Self = Self;
-
-    const MAX: Self = Self;
-    const MAX_USIZE: usize = 0;
-
-    #[inline]
-    fn one() -> Self {
-        panic!("ZeroLenType cannot represent value 1");
-    }
-}
-
-impl LenType for ZeroLenType {}
-
-impl Add for ZeroLenType {
-    type Output = Self;
-
-    fn add(self, _rhs: Self) -> Self::Output {
-        Self::ZERO
-    }
-}
-
-impl AddAssign for ZeroLenType {
-    fn add_assign(&mut self, _rhs: Self) {}
-}
-
-impl Sub for ZeroLenType {
-    type Output = Self;
-
-    fn sub(self, _rhs: Self) -> Self::Output {
-        Self::ZERO
-    }
-}
-
-impl SubAssign for ZeroLenType {
-    fn sub_assign(&mut self, _rhs: Self) {}
-}
-
-#[doc(hidden)]
-#[derive(Debug, PartialEq)]
-pub struct ZeroLenTypeTryFromError;
-
-impl TryFrom<usize> for ZeroLenType {
-    type Error = ZeroLenTypeTryFromError;
-
-    fn try_from(value: usize) -> Result<Self, Self::Error> {
-        if value > 0 {
-            return Err(ZeroLenTypeTryFromError);
-        }
-
-        Ok(Self::ZERO)
-    }
-}
-
-impl TryInto<usize> for ZeroLenType {
-    type Error = ();
-
-    fn try_into(self) -> Result<usize, Self::Error> {
-        Ok(0)
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::len_type::{Sealed, ZeroLenType, ZeroLenTypeTryFromError};
-
-    #[test]
-    pub fn test_zero_len_type_conversions() {
-        assert_eq!(ZeroLenType::into_usize(ZeroLenType::ZERO), 0_usize);
-        assert_eq!(ZeroLenType::from_usize(0_usize), ZeroLenType::ZERO);
-
-        assert_eq!(ZeroLenType::ZERO.try_into(), Ok(0_usize));
-        assert_eq!(ZeroLenType::try_from(0_usize), Ok(ZeroLenType::ZERO));
-        assert_eq!(ZeroLenType::try_from(1_usize), Err(ZeroLenTypeTryFromError));
-    }
-
-    #[test]
-    #[should_panic]
-    pub fn test_zero_len_type_one() {
-        ZeroLenType::one();
-    }
-
-    #[test]
-    #[should_panic]
-    pub fn test_zero_len_type_one_usize() {
-        ZeroLenType::from_usize(1);
-    }
-
-    #[test]
-    pub fn test_zero_len_type_constants() {
-        assert_eq!(ZeroLenType::ZERO, ZeroLenType);
-        assert_eq!(ZeroLenType::MAX, ZeroLenType);
-        assert_eq!(ZeroLenType::MAX_USIZE, 0_usize);
-    }
-
-    #[test]
-    pub fn test_zero_len_type_size() {
-        assert_eq!(core::mem::size_of::<ZeroLenType>(), 0);
-    }
-
-    #[test]
-    pub fn test_zero_len_type_ops() {
-        assert_eq!(ZeroLenType::ZERO + ZeroLenType::ZERO, ZeroLenType::ZERO);
-        assert_eq!(ZeroLenType::ZERO - ZeroLenType::ZERO, ZeroLenType::ZERO);
-
-        let mut zero = ZeroLenType::ZERO;
-        zero += ZeroLenType::ZERO;
-        assert_eq!(zero, ZeroLenType::ZERO);
-        zero -= ZeroLenType::ZERO;
-        assert_eq!(zero, ZeroLenType::ZERO);
-    }
-
-    #[test]
-    pub fn test_zero_len_type_debug() {
-        assert_eq!(format!("{}", ZeroLenType), "0");
-        assert_eq!(format!("{:?}", ZeroLenType), "0");
-    }
-}
diff --git a/src/lib.rs b/src/lib.rs
index 80c57dfd8b..f9880690cf 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -241,7 +241,6 @@ mod ufmt;
 /// Do not use. Used for macros only. Not covered by semver guarantees.
 #[doc(hidden)]
 pub mod _export {
-    pub use crate::len_type::DefaultLenType;
     pub use crate::string::format;
 }
 
diff --git a/src/sorted_linked_list.rs b/src/sorted_linked_list.rs
index 899de283fd..d319fe0f6d 100644
--- a/src/sorted_linked_list.rs
+++ b/src/sorted_linked_list.rs
@@ -8,7 +8,7 @@
 //!
 //! ```
 //! use heapless::sorted_linked_list::{Max, SortedLinkedList};
-//! let mut ll: SortedLinkedList<_, Max, 3> = SortedLinkedList::new_u8();
+//! let mut ll: SortedLinkedList<_, Max, 3, u8> = SortedLinkedList::new_u8();
 //!
 //! // The largest value will always be first
 //! ll.push(1).unwrap();
@@ -156,7 +156,7 @@ pub use storage::{
     OwnedSortedLinkedListStorage, SortedLinkedListStorage, ViewSortedLinkedListStorage,
 };
 
-use crate::len_type::{DefaultLenType, LenType};
+use crate::len_type::LenType;
 
 /// Marker for Min sorted [`SortedLinkedList`].
 pub struct Min;
@@ -212,7 +212,7 @@ where
 }
 
 /// The linked list.
-pub type SortedLinkedList<T, K, const N: usize, Idx = DefaultLenType<N>> =
+pub type SortedLinkedList<T, K, const N: usize, Idx = usize> =
     SortedLinkedListInner<T, Idx, K, OwnedSortedLinkedListStorage<T, Idx, N>>;
 
 /// The linked list.
@@ -391,7 +391,7 @@ where
     ///
     /// ```
     /// use heapless::sorted_linked_list::{Max, SortedLinkedList};
-    /// let mut ll: SortedLinkedList<_, Max, 3> = SortedLinkedList::new_u8();
+    /// let mut ll: SortedLinkedList<_, Max, 3, u8> = SortedLinkedList::new_u8();
     ///
     /// // The largest value will always be first
     /// ll.push(1).unwrap();
@@ -421,7 +421,7 @@ where
     ///
     /// ```
     /// use heapless::sorted_linked_list::{Max, Min, SortedLinkedList};
-    /// let mut ll_max: SortedLinkedList<_, Max, 3> = SortedLinkedList::new_u8();
+    /// let mut ll_max: SortedLinkedList<_, Max, 3, u8> = SortedLinkedList::new_u8();
     ///
     /// // The largest value will always be first
     /// ll_max.push(1).unwrap();
@@ -431,7 +431,7 @@ where
     /// ll_max.push(3).unwrap();
     /// assert_eq!(ll_max.peek(), Some(&3));
     ///
-    /// let mut ll_min: SortedLinkedList<_, Min, 3> = SortedLinkedList::new_u8();
+    /// let mut ll_min: SortedLinkedList<_, Min, 3, u8> = SortedLinkedList::new_u8();
     ///
     /// // The Smallest value will always be first
     /// ll_min.push(3).unwrap();
@@ -470,7 +470,7 @@ where
     ///
     /// ```
     /// use heapless::sorted_linked_list::{Max, SortedLinkedList};
-    /// let mut ll: SortedLinkedList<_, Max, 3> = SortedLinkedList::new_u8();
+    /// let mut ll: SortedLinkedList<_, Max, 3, u8> = SortedLinkedList::new_u8();
     ///
     /// ll.push(1).unwrap();
     /// ll.push(2).unwrap();
@@ -493,7 +493,7 @@ where
     ///
     /// ```
     /// use heapless::sorted_linked_list::{Max, SortedLinkedList};
-    /// let mut ll: SortedLinkedList<_, Max, 3> = SortedLinkedList::new_u8();
+    /// let mut ll: SortedLinkedList<_, Max, 3, u8> = SortedLinkedList::new_u8();
     ///
     /// assert_eq!(ll.is_full(), false);
     ///
@@ -515,7 +515,7 @@ where
     ///
     /// ```
     /// use heapless::sorted_linked_list::{Max, SortedLinkedList};
-    /// let mut ll: SortedLinkedList<_, Max, 3> = SortedLinkedList::new_u8();
+    /// let mut ll: SortedLinkedList<_, Max, 3, u8> = SortedLinkedList::new_u8();
     ///
     /// assert_eq!(ll.is_empty(), true);
     ///
@@ -541,7 +541,7 @@ where
     ///
     /// ```
     /// use heapless::sorted_linked_list::{Max, SortedLinkedList};
-    /// let mut ll: SortedLinkedList<_, Max, 3> = SortedLinkedList::new_u8();
+    /// let mut ll: SortedLinkedList<_, Max, 3, u8> = SortedLinkedList::new_u8();
     ///
     /// ll.push(1).unwrap();
     /// ll.push(2).unwrap();
@@ -565,7 +565,7 @@ where
     ///
     /// ```
     /// use heapless::sorted_linked_list::{Max, SortedLinkedList};
-    /// let mut ll: SortedLinkedList<_, Max, 3> = SortedLinkedList::new_u8();
+    /// let mut ll: SortedLinkedList<_, Max, 3, u8> = SortedLinkedList::new_u8();
     ///
     /// ll.push(1).unwrap();
     /// ll.push(2).unwrap();
@@ -695,7 +695,7 @@ where
     ///
     /// ```
     /// use heapless::sorted_linked_list::{Max, SortedLinkedList};
-    /// let mut ll: SortedLinkedList<_, Max, 3> = SortedLinkedList::new_u8();
+    /// let mut ll: SortedLinkedList<_, Max, 3, u8> = SortedLinkedList::new_u8();
     ///
     /// ll.push(1).unwrap();
     /// ll.push(2).unwrap();
@@ -725,7 +725,7 @@ where
     ///
     /// ```
     /// use heapless::sorted_linked_list::{Max, SortedLinkedList};
-    /// let mut ll: SortedLinkedList<_, Max, 3> = SortedLinkedList::new_u8();
+    /// let mut ll: SortedLinkedList<_, Max, 3, u8> = SortedLinkedList::new_u8();
     ///
     /// ll.push(1).unwrap();
     /// ll.push(2).unwrap();
@@ -863,7 +863,7 @@ mod tests {
 
     #[test]
     fn test_peek() {
-        let mut ll: SortedLinkedList<u32, Max, 3> = SortedLinkedList::new_u8();
+        let mut ll: SortedLinkedList<u32, Max, 3, u8> = SortedLinkedList::new_u8();
 
         ll.push(1).unwrap();
         assert_eq!(ll.peek().unwrap(), &1);
@@ -874,7 +874,7 @@ mod tests {
         ll.push(3).unwrap();
         assert_eq!(ll.peek().unwrap(), &3);
 
-        let mut ll: SortedLinkedList<u32, Min, 3> = SortedLinkedList::new_u8();
+        let mut ll: SortedLinkedList<u32, Min, 3, u8> = SortedLinkedList::new_u8();
 
         ll.push(2).unwrap();
         assert_eq!(ll.peek().unwrap(), &2);
@@ -888,7 +888,7 @@ mod tests {
 
     #[test]
     fn test_full() {
-        let mut ll: SortedLinkedList<u32, Max, 3> = SortedLinkedList::new_u8();
+        let mut ll: SortedLinkedList<u32, Max, 3, u8> = SortedLinkedList::new_u8();
         ll.push(1).unwrap();
         ll.push(2).unwrap();
         ll.push(3).unwrap();
@@ -898,7 +898,7 @@ mod tests {
 
     #[test]
     fn test_empty() {
-        let ll: SortedLinkedList<u32, Max, 3> = SortedLinkedList::new_u8();
+        let ll: SortedLinkedList<u32, Max, 3, u8> = SortedLinkedList::new_u8();
 
         assert!(ll.is_empty());
     }
@@ -913,7 +913,7 @@ mod tests {
 
     #[test]
     fn test_rejected_push() {
-        let mut ll: SortedLinkedList<u32, Max, 3> = SortedLinkedList::new_u8();
+        let mut ll: SortedLinkedList<u32, Max, 3, u8> = SortedLinkedList::new_u8();
         ll.push(1).unwrap();
         ll.push(2).unwrap();
         ll.push(3).unwrap();
@@ -926,7 +926,7 @@ mod tests {
 
     #[test]
     fn test_updating() {
-        let mut ll: SortedLinkedList<u32, Max, 3> = SortedLinkedList::new_u8();
+        let mut ll: SortedLinkedList<u32, Max, 3, u8> = SortedLinkedList::new_u8();
         ll.push(1).unwrap();
         ll.push(2).unwrap();
         ll.push(3).unwrap();
@@ -953,7 +953,7 @@ mod tests {
 
     #[test]
     fn test_updating_1() {
-        let mut ll: SortedLinkedList<u32, Max, 3> = SortedLinkedList::new_u8();
+        let mut ll: SortedLinkedList<u32, Max, 3, u8> = SortedLinkedList::new_u8();
         ll.push(1).unwrap();
 
         let v = ll.pop().unwrap();
@@ -963,7 +963,7 @@ mod tests {
 
     #[test]
     fn test_updating_2() {
-        let mut ll: SortedLinkedList<u32, Max, 3> = SortedLinkedList::new_u8();
+        let mut ll: SortedLinkedList<u32, Max, 3, u8> = SortedLinkedList::new_u8();
         ll.push(1).unwrap();
 
         let mut find = ll.find_mut(|v| *v == 1).unwrap();
diff --git a/src/string/mod.rs b/src/string/mod.rs
index e58a542d76..668dc95407 100644
--- a/src/string/mod.rs
+++ b/src/string/mod.rs
@@ -11,7 +11,7 @@ use core::{
     str::{self, Utf8Error},
 };
 
-use crate::{len_type::DefaultLenType, CapacityError};
+use crate::CapacityError;
 use crate::{
     len_type::LenType,
     vec::{OwnedVecStorage, Vec, VecInner, ViewVecStorage},
@@ -147,10 +147,10 @@ pub struct StringInner<LenT: LenType, S: StringStorage + ?Sized> {
 }
 
 /// A fixed capacity [`String`](https://doc.rust-lang.org/std/string/struct.String.html).
-pub type String<const N: usize, LenT = DefaultLenType<N>> = StringInner<LenT, OwnedStorage<N>>;
+pub type String<const N: usize, LenT = usize> = StringInner<LenT, OwnedStorage<N>>;
 
 /// A dynamic capacity [`String`](https://doc.rust-lang.org/std/string/struct.String.html).
-pub type StringView<LenT> = StringInner<LenT, ViewStorage>;
+pub type StringView<LenT = usize> = StringInner<LenT, ViewStorage>;
 
 impl<LenT: LenType, const N: usize> String<N, LenT> {
     /// Constructs a new, empty `String` with a fixed capacity of `N` bytes.
@@ -368,7 +368,7 @@ impl<LenT: LenType, S: StringStorage + ?Sized> StringInner<LenT, S> {
     /// ```rust
     /// # use heapless::string::{String, StringView};
     /// let s: String<10, _> = String::try_from("hello").unwrap();
-    /// let view: &StringView<u8> = s.as_view();
+    /// let view: &StringView = s.as_view();
     /// ```
     ///
     /// It is often preferable to do the same through type coerction, since `String<N>` implements `Unsize<StringView>`:
@@ -376,7 +376,7 @@ impl<LenT: LenType, S: StringStorage + ?Sized> StringInner<LenT, S> {
     /// ```rust
     /// # use heapless::string::{String, StringView};
     /// let s: String<10, _> = String::try_from("hello").unwrap();
-    /// let view: &StringView<u8> = &s;
+    /// let view: &StringView = &s;
     /// ```
     #[inline]
     pub fn as_view(&self) -> &StringView<LenT> {
@@ -389,7 +389,7 @@ impl<LenT: LenType, S: StringStorage + ?Sized> StringInner<LenT, S> {
     /// ```rust
     /// # use heapless::string::{String, StringView};
     /// let mut s: String<10> = String::try_from("hello").unwrap();
-    /// let view: &mut StringView<_> = s.as_mut_view();
+    /// let view: &mut StringView = s.as_mut_view();
     /// ```
     ///
     /// It is often preferable to do the same through type coerction, since `String<N>` implements `Unsize<StringView>`:
@@ -397,7 +397,7 @@ impl<LenT: LenType, S: StringStorage + ?Sized> StringInner<LenT, S> {
     /// ```rust
     /// # use heapless::string::{String, StringView};
     /// let mut s: String<10> = String::try_from("hello").unwrap();
-    /// let view: &mut StringView<_> = &mut s;
+    /// let view: &mut StringView = &mut s;
     /// ```
     #[inline]
     pub fn as_mut_view(&mut self) -> &mut StringView<LenT> {
@@ -938,8 +938,12 @@ pub fn format<const N: usize, LenT: LenType>(
 macro_rules! format {
     // Without semicolon as separator to disambiguate between arms, Rust just
     // chooses the first so that the format string would land in $max.
+    ($max:expr; $lenT:path; $($arg:tt)*) => {{
+        let res = $crate::_export::format::<$max, $lenT>(core::format_args!($($arg)*));
+        res
+    }};
     ($max:expr; $($arg:tt)*) => {{
-        let res = $crate::_export::format::<$max, $crate::_export::DefaultLenType<$max>>(core::format_args!($($arg)*));
+        let res = $crate::_export::format::<$max, usize>(core::format_args!($($arg)*));
         res
     }};
     ($($arg:tt)*) => {{
@@ -1236,29 +1240,4 @@ mod tests {
         let formatted = format!(2; "123");
         assert_eq!(formatted, Err(core::fmt::Error));
     }
-
-    #[test]
-    fn zero_capacity() {
-        let mut s: String<0> = String::new();
-        // Validate capacity
-        assert_eq!(s.capacity(), 0);
-
-        // Make sure there is no capacity
-        assert!(s.push('a').is_err());
-
-        // Validate length
-        assert_eq!(s.len(), 0);
-
-        // Validate pop
-        assert_eq!(s.pop(), None);
-
-        // Validate slice
-        assert_eq!(s.as_str(), "");
-
-        // Validate empty
-        assert!(s.is_empty());
-
-        // Size of string with zero capacity should be 0 bytes because of `ZeroLenType` optimization
-        assert_eq!(core::mem::size_of_val(&s), 0);
-    }
 }
diff --git a/src/vec/mod.rs b/src/vec/mod.rs
index 13ffeaab73..9eccbfab62 100644
--- a/src/vec/mod.rs
+++ b/src/vec/mod.rs
@@ -11,7 +11,7 @@ use core::{
     slice,
 };
 
-use crate::len_type::{check_capacity_fits, DefaultLenType, LenType};
+use crate::len_type::{check_capacity_fits, LenType};
 use crate::CapacityError;
 
 mod drain;
@@ -255,8 +255,7 @@ pub struct VecInner<T, LenT: LenType, S: VecStorage<T> + ?Sized> {
 /// For uncommmon capacity values, or in generic scenarios, you may have to provide the `LenT` generic yourself.
 ///
 /// This should be the smallest unsigned integer type that your capacity fits in, or `usize` if you don't want to consider this.
-pub type Vec<T, const N: usize, LenT = DefaultLenType<N>> =
-    VecInner<T, LenT, OwnedVecStorage<T, N>>;
+pub type Vec<T, const N: usize, LenT = usize> = VecInner<T, LenT, OwnedVecStorage<T, N>>;
 
 /// A [`Vec`] with dynamic capacity
 ///
@@ -1806,7 +1805,7 @@ mod tests {
         {
             let v: Vec<Droppable, 2> = Vec::new();
             let v: Box<Vec<Droppable, 2>> = Box::new(v);
-            let mut v: Box<VecView<Droppable, u8>> = v;
+            let mut v: Box<VecView<Droppable>> = v;
             v.push(Droppable::new()).ok().unwrap();
             v.push(Droppable::new()).ok().unwrap();
             assert_eq!(Droppable::count(), 2);
@@ -1819,7 +1818,7 @@ mod tests {
         {
             let v: Vec<Droppable, 2> = Vec::new();
             let v: Box<Vec<Droppable, 2>> = Box::new(v);
-            let mut v: Box<VecView<Droppable, u8>> = v;
+            let mut v: Box<VecView<Droppable>> = v;
             v.push(Droppable::new()).ok().unwrap();
             v.push(Droppable::new()).ok().unwrap();
             assert_eq!(Droppable::count(), 2);
@@ -2181,34 +2180,6 @@ mod tests {
         assert!(!v.ends_with(b"a"));
     }
 
-    #[test]
-    fn zero_capacity() {
-        let mut v: Vec<u8, 0> = Vec::new();
-        // Validate capacity
-        assert_eq!(v.capacity(), 0);
-
-        // Make sure there is no capacity
-        assert!(v.push(1).is_err());
-
-        // Validate length
-        assert_eq!(v.len(), 0);
-
-        // Validate pop
-        assert_eq!(v.pop(), None);
-
-        // Validate slice
-        assert_eq!(v.as_slice(), &[]);
-
-        // Validate empty
-        assert!(v.is_empty());
-
-        // Validate full
-        assert!(v.is_full());
-
-        // Size of vector with zero capacity should be 0 bytes because of `ZeroLenType` optimization
-        assert_eq!(core::mem::size_of_val(&v), 0);
-    }
-
     #[test]
     fn spare_capacity_mut() {
         let mut v: Vec<_, 4> = Vec::new();