diff --git a/Cargo.lock b/Cargo.lock
index 6cf2ba73..de8dd489 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2911,7 +2911,6 @@ dependencies = [
 name = "mas-jose"
 version = "0.1.0"
 dependencies = [
- "anyhow",
  "base64ct",
  "chrono",
  "digest 0.10.6",
diff --git a/crates/handlers/src/oauth2/token.rs b/crates/handlers/src/oauth2/token.rs
index f15416b0..bf37121d 100644
--- a/crates/handlers/src/oauth2/token.rs
+++ b/crates/handlers/src/oauth2/token.rs
@@ -23,7 +23,7 @@ use mas_axum_utils::client_authorization::{ClientAuthorization, CredentialsVerif
 use mas_data_model::{AuthorizationGrantStage, Client, TokenType};
 use mas_iana::jose::JsonWebSignatureAlg;
 use mas_jose::{
-    claims::{self, hash_token, ClaimError},
+    claims::{self, hash_token, ClaimError, TokenHashError},
     constraints::Constrainable,
     jwt::{JsonWebSignatureHeader, Jwt, JwtSignatureError},
 };
@@ -177,6 +177,12 @@ impl From<ClaimError> for RouteError {
     }
 }
 
+impl From<TokenHashError> for RouteError {
+    fn from(e: TokenHashError) -> Self {
+        Self::Internal(Box::new(e))
+    }
+}
+
 impl From<JwtSignatureError> for RouteError {
     fn from(e: JwtSignatureError) -> Self {
         Self::Internal(Box::new(e))
diff --git a/crates/jose/Cargo.toml b/crates/jose/Cargo.toml
index b4a48b9e..62f09612 100644
--- a/crates/jose/Cargo.toml
+++ b/crates/jose/Cargo.toml
@@ -6,7 +6,6 @@ edition = "2021"
 license = "Apache-2.0"
 
 [dependencies]
-anyhow = "1.0.66"
 base64ct = { version = "1.5.3", features = ["std"] }
 chrono = { version = "0.4.23", features = ["serde"] }
 digest = "0.10.6"
diff --git a/crates/jose/src/claims.rs b/crates/jose/src/claims.rs
index d16f923f..d4a2a8ff 100644
--- a/crates/jose/src/claims.rs
+++ b/crates/jose/src/claims.rs
@@ -12,9 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::{collections::HashMap, marker::PhantomData, ops::Deref};
+use std::{collections::HashMap, convert::Infallible, marker::PhantomData, ops::Deref};
 
-use anyhow::Context;
 use base64ct::{Base64UrlUnpadded, Encoding};
 use mas_iana::jose::JsonWebSignatureAlg;
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
@@ -33,16 +32,19 @@ pub enum ClaimError {
     ValidationError {
         claim: &'static str,
         #[source]
-        source: anyhow::Error,
+        source: Box<dyn std::error::Error + Send + Sync + 'static>,
     },
 }
 
 pub trait Validator<T> {
-    fn validate(&self, value: &T) -> Result<(), anyhow::Error>;
+    type Error;
+    fn validate(&self, value: &T) -> Result<(), Self::Error>;
 }
 
 impl<T> Validator<T> for () {
-    fn validate(&self, _value: &T) -> Result<(), anyhow::Error> {
+    type Error = Infallible;
+
+    fn validate(&self, _value: &T) -> Result<(), Self::Error> {
         Ok(())
     }
 }
@@ -53,7 +55,10 @@ pub struct Claim<T, V = ()> {
     v: PhantomData<V>,
 }
 
-impl<T, V> Claim<T, V> {
+impl<T, V> Claim<T, V>
+where
+    V: Validator<T>,
+{
     #[must_use]
     pub const fn new(claim: &'static str) -> Self {
         Self {
@@ -86,7 +91,8 @@ impl<T, V> Claim<T, V> {
     ) -> Result<T, ClaimError>
     where
         T: DeserializeOwned,
-        V: Default + Validator<T>,
+        V: Default,
+        V::Error: std::error::Error + Send + Sync + 'static,
     {
         let validator = V::default();
         self.extract_required_with_options(claims, validator)
@@ -100,7 +106,7 @@ impl<T, V> Claim<T, V> {
     where
         T: DeserializeOwned,
         I: Into<V>,
-        V: Validator<T>,
+        V::Error: std::error::Error + Send + Sync + 'static,
     {
         let validator: V = validator.into();
         let claim = claims
@@ -113,7 +119,7 @@ impl<T, V> Claim<T, V> {
             .validate(&res)
             .map_err(|source| ClaimError::ValidationError {
                 claim: self.claim,
-                source,
+                source: Box::new(source),
             })?;
         Ok(res)
     }
@@ -124,7 +130,8 @@ impl<T, V> Claim<T, V> {
     ) -> Result<Option<T>, ClaimError>
     where
         T: DeserializeOwned,
-        V: Default + Validator<T>,
+        V: Default,
+        V::Error: std::error::Error + Send + Sync + 'static,
     {
         let validator = V::default();
         self.extract_optional_with_options(claims, validator)
@@ -138,7 +145,7 @@ impl<T, V> Claim<T, V> {
     where
         T: DeserializeOwned,
         I: Into<V>,
-        V: Validator<T>,
+        V::Error: std::error::Error + Send + Sync + 'static,
     {
         match self.extract_required_with_options(claims, validator) {
             Ok(v) => Ok(Some(v)),
@@ -170,15 +177,20 @@ impl TimeOptions {
     }
 }
 
+#[derive(Debug, Clone, Copy, Error)]
+#[error("Current time is too far away")]
+pub struct TimeTooFarError;
+
 #[derive(Debug, Clone)]
 pub struct TimeNotAfter(TimeOptions);
 
 impl Validator<Timestamp> for TimeNotAfter {
-    fn validate(&self, value: &Timestamp) -> Result<(), anyhow::Error> {
+    type Error = TimeTooFarError;
+    fn validate(&self, value: &Timestamp) -> Result<(), Self::Error> {
         if self.0.when <= value.0 + self.0.leeway {
             Ok(())
         } else {
-            Err(anyhow::anyhow!("current time is too far away"))
+            Err(TimeTooFarError)
         }
     }
 }
@@ -199,11 +211,13 @@ impl From<&TimeOptions> for TimeNotAfter {
 pub struct TimeNotBefore(TimeOptions);
 
 impl Validator<Timestamp> for TimeNotBefore {
-    fn validate(&self, value: &Timestamp) -> Result<(), anyhow::Error> {
+    type Error = TimeTooFarError;
+
+    fn validate(&self, value: &Timestamp) -> Result<(), Self::Error> {
         if self.0.when >= value.0 - self.0.leeway {
             Ok(())
         } else {
-            Err(anyhow::anyhow!("current time is too far before"))
+            Err(TimeTooFarError)
         }
     }
 }
@@ -229,7 +243,7 @@ impl From<&TimeOptions> for TimeNotBefore {
 /// Returns an error if the algorithm is not supported.
 ///
 /// [OpenID Connect Core 1.0 specification]: https://openid.net/specs/openid-connect-core-1_0.html#CodeIDToken
-pub fn hash_token(alg: &JsonWebSignatureAlg, token: &str) -> anyhow::Result<String> {
+pub fn hash_token(alg: &JsonWebSignatureAlg, token: &str) -> Result<String, TokenHashError> {
     let bits = match alg {
         JsonWebSignatureAlg::Hs256
         | JsonWebSignatureAlg::Rs256
@@ -238,9 +252,9 @@ pub fn hash_token(alg: &JsonWebSignatureAlg, token: &str) -> anyhow::Result<Stri
         | JsonWebSignatureAlg::Es256K => {
             let mut hasher = Sha256::new();
             hasher.update(token);
-            let hash = hasher.finalize();
+            let hash: [u8; 32] = hasher.finalize().into();
             // Left-most half
-            hash.get(..16).map(ToOwned::to_owned)
+            hash[..16].to_owned()
         }
         JsonWebSignatureAlg::Hs384
         | JsonWebSignatureAlg::Rs384
@@ -248,9 +262,9 @@ pub fn hash_token(alg: &JsonWebSignatureAlg, token: &str) -> anyhow::Result<Stri
         | JsonWebSignatureAlg::Ps384 => {
             let mut hasher = Sha384::new();
             hasher.update(token);
-            let hash = hasher.finalize();
+            let hash: [u8; 48] = hasher.finalize().into();
             // Left-most half
-            hash.get(..24).map(ToOwned::to_owned)
+            hash[..24].to_owned()
         }
         JsonWebSignatureAlg::Hs512
         | JsonWebSignatureAlg::Rs512
@@ -258,17 +272,25 @@ pub fn hash_token(alg: &JsonWebSignatureAlg, token: &str) -> anyhow::Result<Stri
         | JsonWebSignatureAlg::Ps512 => {
             let mut hasher = Sha512::new();
             hasher.update(token);
-            let hash = hasher.finalize();
+            let hash: [u8; 64] = hasher.finalize().into();
             // Left-most half
-            hash.get(..32).map(ToOwned::to_owned)
+            hash[..32].to_owned()
         }
-        _ => return Err(anyhow::anyhow!("unsupported algorithm for hashing")),
-    }
-    .context("failed to get first half of hash")?;
+        _ => return Err(TokenHashError::UnsupportedAlgorithm),
+    };
 
     Ok(Base64UrlUnpadded::encode_string(&bits))
 }
 
+#[derive(Debug, Clone, Copy, Error)]
+pub enum TokenHashError {
+    #[error("Hashes don't match")]
+    HashMismatch,
+
+    #[error("Unsupported algorithm for hashing")]
+    UnsupportedAlgorithm,
+}
+
 #[derive(Debug, Clone)]
 pub struct TokenHash<'a> {
     alg: &'a JsonWebSignatureAlg,
@@ -284,15 +306,20 @@ impl<'a> TokenHash<'a> {
 }
 
 impl<'a> Validator<String> for TokenHash<'a> {
-    fn validate(&self, value: &String) -> Result<(), anyhow::Error> {
+    type Error = TokenHashError;
+    fn validate(&self, value: &String) -> Result<(), Self::Error> {
         if hash_token(self.alg, self.token)? == *value {
             Ok(())
         } else {
-            Err(anyhow::anyhow!("hashes don't match"))
+            Err(TokenHashError::HashMismatch)
         }
     }
 }
 
+#[derive(Debug, Clone, Copy, Error)]
+#[error("Values don't match")]
+pub struct EqualityError;
+
 #[derive(Debug, Clone)]
 pub struct Equality<'a, T: ?Sized> {
     value: &'a T,
@@ -310,11 +337,12 @@ impl<'a, T1, T2: ?Sized> Validator<T1> for Equality<'a, T2>
 where
     T2: PartialEq<T1>,
 {
-    fn validate(&self, value: &T1) -> Result<(), anyhow::Error> {
+    type Error = EqualityError;
+    fn validate(&self, value: &T1) -> Result<(), Self::Error> {
         if *self.value == *value {
             Ok(())
         } else {
-            Err(anyhow::anyhow!("values don't match"))
+            Err(EqualityError)
         }
     }
 }
@@ -338,15 +366,20 @@ impl<'a, T> Contains<'a, T> {
     }
 }
 
+#[derive(Debug, Clone, Copy, Error)]
+#[error("OneOrMany doesn't contains value")]
+pub struct ContainsError;
+
 impl<'a, T> Validator<OneOrMany<T>> for Contains<'a, T>
 where
     T: PartialEq,
 {
-    fn validate(&self, value: &OneOrMany<T>) -> Result<(), anyhow::Error> {
+    type Error = ContainsError;
+    fn validate(&self, value: &OneOrMany<T>) -> Result<(), Self::Error> {
         if value.contains(self.value) {
             Ok(())
         } else {
-            Err(anyhow::anyhow!("OneOrMany doesn't contain value"))
+            Err(ContainsError)
         }
     }
 }