diff --git a/benchmarks/compile/Cargo.toml b/benchmarks/compile/Cargo.toml
index 44eb302..f4f0b8b 100644
--- a/benchmarks/compile/Cargo.toml
+++ b/benchmarks/compile/Cargo.toml
@@ -17,11 +17,7 @@ structs-10-fields-10 = []
 validator = ["dep:validator"]
 
 [dependencies]
-fortifier = { workspace = true, features = [
-    "email-address",
-    "serde",
-    "url",
-], optional = true }
+fortifier = { workspace = true, features = ["email-address", "serde", "url"], optional = true }
 validator = { version = "0.20.0", features = ["derive"], optional = true }
 
 [lints]
diff --git a/examples/basic/Cargo.toml b/examples/basic/Cargo.toml
index 7162eaf..4a2f0dc 100644
--- a/examples/basic/Cargo.toml
+++ b/examples/basic/Cargo.toml
@@ -10,12 +10,7 @@ repository.workspace = true
 version.workspace = true
 
 [dependencies]
-fortifier = { workspace = true, features = [
-    "email-address",
-    "phone-number",
-    "regex",
-    "url",
-] }
+fortifier = { workspace = true, features = ["email-address", "phone-number", "regex", "url"] }
 regex.workspace = true
 tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }
 
diff --git a/examples/server/Cargo.toml b/examples/server/Cargo.toml
index eefa40c..5733913 100644
--- a/examples/server/Cargo.toml
+++ b/examples/server/Cargo.toml
@@ -11,13 +11,7 @@ version.workspace = true
 
 [dependencies]
 axum = "0.8.7"
-fortifier = { workspace = true, features = [
-    "email-address",
-    "regex",
-    "serde",
-    "url",
-    "utoipa",
-] }
+fortifier = { workspace = true, features = ["email-address", "regex", "serde", "url", "utoipa"] }
 serde = { workspace = true, features = ["derive"] }
 thiserror = "2.0.17"
 tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }
diff --git a/packages/fortifier-macros-tests/Cargo.toml b/packages/fortifier-macros-tests/Cargo.toml
index dfc7430..e94d071 100644
--- a/packages/fortifier-macros-tests/Cargo.toml
+++ b/packages/fortifier-macros-tests/Cargo.toml
@@ -22,11 +22,7 @@ ignored = ["chrono", "rust_decimal", "uuid"]
 chrono.workspace = true
 constant-string.workspace = true
 email_address.workspace = true
-fortifier = { workspace = true, features = [
-    "all-types",
-    "all-validations",
-    "serde",
-] }
+fortifier = { workspace = true, features = ["all-types", "all-validations", "serde"] }
 indexmap.workspace = true
 phonenumber.workspace = true
 pretty_assertions.workspace = true
diff --git a/packages/fortifier/src/validations/length.rs b/packages/fortifier/src/validations/length.rs
index 7823f22..542204a 100644
--- a/packages/fortifier/src/validations/length.rs
+++ b/packages/fortifier/src/validations/length.rs
@@ -37,7 +37,7 @@ pub enum LengthError<T> {
 
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: LengthErrorCode,
 
         /// A human-readable error message.
@@ -54,7 +54,7 @@ pub enum LengthError<T> {
 
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: LengthErrorCode,
 
         /// A human-readable error message.
@@ -71,7 +71,7 @@ pub enum LengthError<T> {
 
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: LengthErrorCode,
 
         /// A human-readable error message.
diff --git a/packages/fortifier/src/validations/phone_number.rs b/packages/fortifier/src/validations/phone_number.rs
index b73f90c..96e599a 100644
--- a/packages/fortifier/src/validations/phone_number.rs
+++ b/packages/fortifier/src/validations/phone_number.rs
@@ -30,7 +30,7 @@ pub enum PhoneNumberError {
     NoNumber {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: PhoneNumberErrorCode,
 
         /// A human-readable error message.
@@ -41,7 +41,7 @@ pub enum PhoneNumberError {
     InvalidCountryCode {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: PhoneNumberErrorCode,
 
         /// A human-readable error message.
@@ -52,7 +52,7 @@ pub enum PhoneNumberError {
     TooShortAfterIdd {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: PhoneNumberErrorCode,
 
         /// A human-readable error message.
@@ -63,7 +63,7 @@ pub enum PhoneNumberError {
     TooShortNsn {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: PhoneNumberErrorCode,
 
         /// A human-readable error message.
@@ -74,7 +74,7 @@ pub enum PhoneNumberError {
     TooLong {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: PhoneNumberErrorCode,
 
         /// A human-readable error message.
@@ -85,7 +85,7 @@ pub enum PhoneNumberError {
     MalformedInteger {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: PhoneNumberErrorCode,
 
         /// A human-readable error message.
@@ -96,7 +96,7 @@ pub enum PhoneNumberError {
     DisallowedCountryCode {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: PhoneNumberErrorCode,
 
         /// Allowed country codes.
diff --git a/packages/fortifier/src/validations/range.rs b/packages/fortifier/src/validations/range.rs
index 4435ffb..0f0f839 100644
--- a/packages/fortifier/src/validations/range.rs
+++ b/packages/fortifier/src/validations/range.rs
@@ -33,7 +33,7 @@ pub enum RangeError<T> {
 
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: RangeErrorCode,
 
         /// A human-readable error message.
@@ -50,7 +50,7 @@ pub enum RangeError<T> {
 
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: RangeErrorCode,
 
         /// A human-readable error message.
@@ -67,7 +67,7 @@ pub enum RangeError<T> {
 
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: RangeErrorCode,
 
         /// A human-readable error message.
@@ -84,7 +84,7 @@ pub enum RangeError<T> {
 
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: RangeErrorCode,
 
         /// A human-readable error message.
diff --git a/packages/fortifier/src/validations/regex.rs b/packages/fortifier/src/validations/regex.rs
index bbf2fb7..e7d0c7c 100644
--- a/packages/fortifier/src/validations/regex.rs
+++ b/packages/fortifier/src/validations/regex.rs
@@ -50,7 +50,7 @@ constant_string!(RegexErrorCode, REGEX_ERROR_CODE, "regex");
 pub struct RegexError {
     /// The error code.
     #[cfg_attr(feature = "serde", serde(default))]
-    #[cfg_attr(feature = "utoipa", schema(inline))]
+    #[cfg_attr(feature = "utoipa", schema(inline, required))]
     code: RegexErrorCode,
 
     /// A human-readable error message.
diff --git a/packages/fortifier/src/validations/url.rs b/packages/fortifier/src/validations/url.rs
index c8536d8..61df212 100644
--- a/packages/fortifier/src/validations/url.rs
+++ b/packages/fortifier/src/validations/url.rs
@@ -29,7 +29,7 @@ pub enum UrlError {
     EmptyHost {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: UrlErrorCode,
 
         /// A human-readable error message.
@@ -40,7 +40,7 @@ pub enum UrlError {
     IdnaError {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: UrlErrorCode,
 
         /// A human-readable error message.
@@ -51,7 +51,7 @@ pub enum UrlError {
     InvalidPort {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: UrlErrorCode,
 
         /// A human-readable error message.
@@ -62,7 +62,7 @@ pub enum UrlError {
     InvalidIpv4Address {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: UrlErrorCode,
 
         /// A human-readable error message.
@@ -73,7 +73,7 @@ pub enum UrlError {
     InvalidIpv6Address {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: UrlErrorCode,
 
         /// A human-readable error message.
@@ -84,7 +84,7 @@ pub enum UrlError {
     InvalidDomainCharacter {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: UrlErrorCode,
 
         /// A human-readable error message.
@@ -95,7 +95,7 @@ pub enum UrlError {
     RelativeUrlWithoutBase {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: UrlErrorCode,
 
         /// A human-readable error message.
@@ -106,7 +106,7 @@ pub enum UrlError {
     RelativeUrlWithCannotBeABaseBase {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: UrlErrorCode,
 
         /// A human-readable error message.
@@ -117,7 +117,7 @@ pub enum UrlError {
     SetHostOnCannotBeABaseUrl {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: UrlErrorCode,
 
         /// A human-readable error message.
@@ -128,7 +128,7 @@ pub enum UrlError {
     Overflow {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: UrlErrorCode,
 
         /// A human-readable error message.
@@ -139,7 +139,7 @@ pub enum UrlError {
     Unknown {
         /// The error code.
         #[cfg_attr(feature = "serde", serde(default))]
-        #[cfg_attr(feature = "utoipa", schema(inline))]
+        #[cfg_attr(feature = "utoipa", schema(inline, required))]
         code: UrlErrorCode,
 
         /// A human-readable error message.