diff --git a/Cargo.toml b/Cargo.toml
index b6067c1..91536e6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,7 +2,8 @@
 name = "ulid"
 version = "1.0.0"
 authors = ["dylanhart <dylan96hart@gmail.com>"]
-edition = "2018"
+edition = "2021"
+rust-version = "1.60"
 
 license = "MIT"
 readme = "README.md"
@@ -14,12 +15,12 @@ repository = "https://github.com/dylanhart/ulid-rs"
 
 [features]
 default = ["std"]
-std = ["rand"]
+std = ["rand", "serde?/std", "uuid?/std"]
 
 [dependencies]
-serde = { version = "1.0", features = ["derive"], optional = true }
+serde = { version = "1.0", features = ["derive"], optional = true, default-features = false }
 rand = { version = "0.8", optional = true }
-uuid = { version = "1.1", optional = true }
+uuid = { version = "1.1", optional = true, default-features = false }
 
 [dev-dependencies]
 bencher = "0.1"
@@ -34,3 +35,4 @@ members = ["cli"]
 
 [package.metadata.docs.rs]
 all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index 6b730ec..c6c7cc7 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -2,6 +2,7 @@
 name = "ulid-cli"
 version = "0.3.1"
 authors = ["dylanhart <dylan96hart@gmail.com>", "Kan-Ru Chen <kanru@kanru.info>"]
+rust-version = "1.60"
 
 license = "MIT"
 readme = "../README.md"
@@ -11,7 +12,7 @@ keywords = ["ulid", "uuid", "sortable", "identifier"]
 
 repository = "https://github.com/dylanhart/ulid-rs"
 
-edition = "2018"
+edition = "2021"
 
 [dependencies]
 structopt = "0.2"
diff --git a/src/base32.rs b/src/base32.rs
index e2e012c..c2b5d6a 100644
--- a/src/base32.rs
+++ b/src/base32.rs
@@ -45,6 +45,7 @@ pub enum EncodeError {
 }
 
 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl std::error::Error for EncodeError {}
 
 impl fmt::Display for EncodeError {
@@ -73,6 +74,7 @@ pub fn encode_to(mut value: u128, buffer: &mut [u8]) -> Result<usize, EncodeErro
 }
 
 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 pub fn encode(value: u128) -> String {
     let mut buffer: [u8; ULID_LEN] = [0; ULID_LEN];
 
@@ -91,6 +93,7 @@ pub enum DecodeError {
 }
 
 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl std::error::Error for DecodeError {}
 
 impl fmt::Display for DecodeError {
diff --git a/src/generator.rs b/src/generator.rs
index 772e62d..8e4a657 100644
--- a/src/generator.rs
+++ b/src/generator.rs
@@ -5,6 +5,7 @@ use std::fmt;
 use crate::Ulid;
 
 /// A Ulid generator that provides monotonically increasing Ulids
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 pub struct Generator {
     previous: Ulid,
 }
@@ -152,6 +153,7 @@ impl Default for Generator {
 }
 
 /// Error while trying to generate a monotonic increment in the same millisecond
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 #[derive(Debug, PartialEq, Eq, Hash, Copy, Clone)]
 pub enum MonotonicError {
     /// Would overflow into the next millisecond
diff --git a/src/lib.rs b/src/lib.rs
index 1cfe4a7..14a8693 100755
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -30,6 +30,7 @@
 //!
 //! ```
 #![cfg_attr(not(feature = "std"), no_std)]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 
 #[doc = include_str!("../README.md")]
 #[cfg(all(doctest, feature = "std"))]
@@ -39,6 +40,7 @@ mod base32;
 #[cfg(feature = "std")]
 mod generator;
 #[cfg(feature = "serde")]
+#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
 pub mod serde;
 #[cfg(feature = "std")]
 mod time;
@@ -206,6 +208,7 @@ impl Ulid {
     /// ```
     #[allow(clippy::inherent_to_string_shadow_display)] // Significantly faster than Display::to_string
     #[cfg(feature = "std")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     pub fn to_string(&self) -> String {
         base32::encode(self.0)
     }
@@ -281,6 +284,7 @@ impl Default for Ulid {
 }
 
 #[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl From<Ulid> for String {
     fn from(ulid: Ulid) -> String {
         ulid.to_string()
diff --git a/src/serde.rs b/src/serde.rs
index 829a6bf..0db3290 100644
--- a/src/serde.rs
+++ b/src/serde.rs
@@ -20,13 +20,63 @@ impl Serialize for Ulid {
     }
 }
 
+struct UlidVisitor(&'static str);
+impl<'de> serde::de::Visitor<'de> for UlidVisitor {
+    type Value = Ulid;
+
+    fn expecting(&self, formatter: &mut core::fmt::Formatter) -> core::fmt::Result {
+        formatter.write_str(self.0)
+    }
+
+    fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
+    where
+        E: serde::de::Error,
+    {
+        #[cfg(feature = "uuid")]
+        if matches!(value.len(), 32 | 36 | 38 | 45) {
+            return match uuid::Uuid::try_parse(value) {
+                Ok(a) => Ok(Ulid::from(a)),
+                Err(e) => Err(serde::de::Error::custom(e)),
+            };
+        }
+        Ulid::from_string(value).map_err(serde::de::Error::custom)
+    }
+
+    fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
+    where
+        E: serde::de::Error,
+    {
+        // allow either the 16 bytes as is, or a wrongly typed str
+        match v.len() {
+            16 => {
+                let ptr = v.as_ptr() as *const [u8; 16];
+                Ok(Ulid::from_bytes(*unsafe { &*ptr }))
+            }
+            crate::ULID_LEN => Ulid::from_string(unsafe { core::str::from_utf8_unchecked(v) })
+                .map_err(serde::de::Error::custom),
+            #[cfg(feature = "uuid")]
+            32 | 36 | 38 | 45 => match uuid::Uuid::try_parse_ascii(v) {
+                Ok(a) => Ok(Ulid::from(a)),
+                Err(e) => Err(serde::de::Error::custom(e)),
+            },
+            len => Err(E::invalid_length(len, &self.0)),
+        }
+    }
+
+    fn visit_u128<E>(self, v: u128) -> Result<Self::Value, E>
+    where
+        E: serde::de::Error,
+    {
+        Ok(Ulid(v))
+    }
+}
+
 impl<'de> Deserialize<'de> for Ulid {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
         D: Deserializer<'de>,
     {
-        let deserialized_str = String::deserialize(deserializer)?;
-        Self::from_string(&deserialized_str).map_err(serde::de::Error::custom)
+        deserializer.deserialize_str(UlidVisitor("an ulid string or value"))
     }
 }
 
@@ -50,7 +100,7 @@ impl<'de> Deserialize<'de> for Ulid {
 /// ```
 pub mod ulid_as_u128 {
     use crate::Ulid;
-    use serde::{Deserialize, Deserializer, Serialize, Serializer};
+    use serde::{Deserializer, Serialize, Serializer};
 
     /// Serializes a ULID as a u128 type.
     pub fn serialize<S>(value: &Ulid, serializer: S) -> Result<S::Ok, S::Error>
@@ -65,8 +115,7 @@ pub mod ulid_as_u128 {
     where
         D: Deserializer<'de>,
     {
-        let deserialized_u128 = u128::deserialize(deserializer)?;
-        Ok(Ulid(deserialized_u128))
+        deserializer.deserialize_u128(super::UlidVisitor("an ulid value as u128"))
     }
 }
 
@@ -89,9 +138,10 @@ pub mod ulid_as_u128 {
 /// }
 /// ```
 #[cfg(all(feature = "uuid", feature = "serde"))]
+#[cfg_attr(docsrs, doc(cfg(all(feature = "uuid", feature = "serde"))))]
 pub mod ulid_as_uuid {
     use crate::Ulid;
-    use serde::{Deserialize, Deserializer, Serialize, Serializer};
+    use serde::{Deserializer, Serializer};
     use uuid::Uuid;
 
     /// Converts the ULID to a UUID and serializes it as a string.
@@ -100,7 +150,9 @@ pub mod ulid_as_uuid {
         S: Serializer,
     {
         let uuid: Uuid = (*value).into();
-        uuid.to_string().serialize(serializer)
+        let mut buffer = uuid::Uuid::encode_buffer();
+        let form = uuid.as_hyphenated().encode_lower(&mut buffer);
+        serializer.serialize_str(form)
     }
 
     /// Deserializes a ULID from a string containing a UUID.
@@ -108,8 +160,6 @@ pub mod ulid_as_uuid {
     where
         D: Deserializer<'de>,
     {
-        let de_string = String::deserialize(deserializer)?;
-        let de_uuid = Uuid::parse_str(&de_string).map_err(serde::de::Error::custom)?;
-        Ok(Ulid::from(de_uuid))
+        deserializer.deserialize_str(super::UlidVisitor("an uuid string"))
     }
 }
diff --git a/src/time.rs b/src/time.rs
index 9f736ac..18ac28f 100644
--- a/src/time.rs
+++ b/src/time.rs
@@ -1,6 +1,9 @@
 use crate::{bitmask, Ulid};
 use std::time::{Duration, SystemTime};
 
+/// The standard library can be used to get the current time.
+/// The `std` feature (which is enabled by default) will expose some extra functions to make life easier.
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl Ulid {
     /// Creates a new Ulid with the current time (UTC)
     ///
@@ -10,6 +13,7 @@ impl Ulid {
     ///
     /// let my_ulid = Ulid::new();
     /// ```
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     pub fn new() -> Ulid {
         Ulid::from_datetime(SystemTime::now())
     }
@@ -24,6 +28,7 @@ impl Ulid {
     /// let mut rng = StdRng::from_entropy();
     /// let ulid = Ulid::with_source(&mut rng);
     /// ```
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     pub fn with_source<R: rand::Rng>(source: &mut R) -> Ulid {
         Ulid::from_datetime_with_source(SystemTime::now(), source)
     }
@@ -42,6 +47,7 @@ impl Ulid {
     ///
     /// let ulid = Ulid::from_datetime(SystemTime::now());
     /// ```
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     pub fn from_datetime(datetime: SystemTime) -> Ulid {
         Ulid::from_datetime_with_source(datetime, &mut rand::thread_rng())
     }
@@ -60,6 +66,7 @@ impl Ulid {
     /// let mut rng = StdRng::from_entropy();
     /// let ulid = Ulid::from_datetime_with_source(SystemTime::now(), &mut rng);
     /// ```
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     pub fn from_datetime_with_source<R>(datetime: SystemTime, source: &mut R) -> Ulid
     where
         R: rand::Rng + ?Sized,
@@ -90,6 +97,7 @@ impl Ulid {
     ///     && dt - Duration::from_millis(1) <= ulid.datetime()
     /// );
     /// ```
+    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
     pub fn datetime(&self) -> SystemTime {
         let stamp = self.timestamp_ms();
         SystemTime::UNIX_EPOCH + Duration::from_millis(stamp)
diff --git a/src/uuid.rs b/src/uuid.rs
index ed76e6a..6065c11 100644
--- a/src/uuid.rs
+++ b/src/uuid.rs
@@ -3,12 +3,14 @@
 use crate::Ulid;
 use uuid::Uuid;
 
+#[cfg_attr(docsrs, doc(cfg(feature = "uuid")))]
 impl From<Uuid> for Ulid {
     fn from(uuid: Uuid) -> Self {
         Ulid(uuid.as_u128())
     }
 }
 
+#[cfg_attr(docsrs, doc(cfg(feature = "uuid")))]
 impl From<Ulid> for Uuid {
     fn from(ulid: Ulid) -> Self {
         Uuid::from_u128(ulid.0)
@@ -21,7 +23,14 @@ mod test {
 
     #[test]
     fn uuid_cycle() {
+        #[cfg(feature = "std")]
         let ulid = Ulid::new();
+        #[cfg(not(feature = "std"))]
+        let ulid = Ulid::from_parts(
+            0x0000_1020_3040_5060_u64,
+            0x0000_0000_0000_0102_0304_0506_0708_090A_u128,
+        );
+
         let uuid: Uuid = ulid.into();
         let ulid2: Ulid = uuid.into();
 
@@ -32,11 +41,17 @@ mod test {
     fn uuid_str_cycle() {
         let uuid_txt = "771a3bce-02e9-4428-a68e-b1e7e82b7f9f";
         let ulid_txt = "3Q38XWW0Q98GMAD3NHWZM2PZWZ";
+        let mut buf = uuid::Uuid::encode_buffer();
 
         let ulid: Ulid = Uuid::parse_str(uuid_txt).unwrap().into();
-        assert_eq!(ulid.to_string(), ulid_txt);
+        let ulid_str = ulid.to_str(&mut buf).unwrap();
+        assert_eq!(ulid_str, ulid_txt);
+
+        #[cfg(feature = "std")]
+        assert_eq!(ulid.to_string().as_str(), ulid_txt);
 
         let uuid: Uuid = ulid.into();
-        assert_eq!(uuid.to_string(), uuid_txt);
+        let uuid_str = uuid.hyphenated().encode_lower(&mut buf);
+        assert_eq!(uuid_str, uuid_txt);
     }
 }