diff --git a/src/api/common/signature/error.rs b/src/api/common/signature/error.rs
index a1b353e1..8d86f042 100644
--- a/src/api/common/signature/error.rs
+++ b/src/api/common/signature/error.rs
@@ -11,8 +11,13 @@ pub enum Error {
 	Common(CommonError),
 
 	/// Authorization Header Malformed
-	#[error("Authorization header malformed, unexpected scope: {0}")]
-	AuthorizationHeaderMalformed(String),
+	#[error(
+		"Authorization header malformed, unexpected scope: '{unexpected}', expected: '{expected}'"
+	)]
+	AuthorizationHeaderMalformed {
+		unexpected: String,
+		expected: String,
+	},
 
 	// Category: bad request
 	/// The request contained an invalid UTF-8 sequence in its path or in other parameters
diff --git a/src/api/common/signature/payload.rs b/src/api/common/signature/payload.rs
index ec4558e6..0b0e8de6 100644
--- a/src/api/common/signature/payload.rs
+++ b/src/api/common/signature/payload.rs
@@ -400,7 +400,10 @@ pub fn verify_v4(
 ) -> Result<Key, Error> {
 	let scope_expected = compute_scope(&auth.date, &garage.config.s3_api.s3_region, service);
 	if auth.scope != scope_expected {
-		return Err(Error::AuthorizationHeaderMalformed(auth.scope.to_string()));
+		return Err(Error::AuthorizationHeaderMalformed {
+			unexpected: auth.scope.to_string(),
+			expected: scope_expected,
+		});
 	}
 
 	let key = garage
diff --git a/src/api/k2v/error.rs b/src/api/k2v/error.rs
index 7ce3b073..797eb868 100644
--- a/src/api/k2v/error.rs
+++ b/src/api/k2v/error.rs
@@ -20,8 +20,13 @@ pub enum Error {
 
 	// Category: cannot process
 	/// Authorization Header Malformed
-	#[error("Authorization header malformed, unexpected scope: {0}")]
-	AuthorizationHeaderMalformed(String),
+	#[error(
+		"Authorization header malformed, unexpected scope: '{unexpected}', expected: '{expected}'"
+	)]
+	AuthorizationHeaderMalformed {
+		unexpected: String,
+		expected: String,
+	},
 
 	/// The provided digest (checksum) value was invalid
 	#[error("Invalid digest: {0}")]
@@ -54,9 +59,13 @@ impl From<SignatureError> for Error {
 	fn from(err: SignatureError) -> Self {
 		match err {
 			SignatureError::Common(c) => Self::Common(c),
-			SignatureError::AuthorizationHeaderMalformed(c) => {
-				Self::AuthorizationHeaderMalformed(c)
-			}
+			SignatureError::AuthorizationHeaderMalformed {
+				unexpected,
+				expected,
+			} => Self::AuthorizationHeaderMalformed {
+				unexpected,
+				expected,
+			},
 			SignatureError::InvalidUtf8Str(i) => Self::InvalidUtf8Str(i),
 			SignatureError::InvalidDigest(d) => Self::InvalidDigest(d),
 		}
@@ -72,7 +81,7 @@ impl Error {
 			Error::Common(c) => c.aws_code(),
 			Error::NoSuchKey => "NoSuchKey",
 			Error::NotAcceptable(_) => "NotAcceptable",
-			Error::AuthorizationHeaderMalformed(_) => "AuthorizationHeaderMalformed",
+			Error::AuthorizationHeaderMalformed { .. } => "AuthorizationHeaderMalformed",
 			Error::InvalidBase64(_) => "InvalidBase64",
 			Error::InvalidUtf8Str(_) => "InvalidUtf8String",
 			Error::InvalidCausalityToken => "CausalityToken",
@@ -88,7 +97,7 @@ impl ApiError for Error {
 			Error::Common(c) => c.http_status_code(),
 			Error::NoSuchKey => StatusCode::NOT_FOUND,
 			Error::NotAcceptable(_) => StatusCode::NOT_ACCEPTABLE,
-			Error::AuthorizationHeaderMalformed(_)
+			Error::AuthorizationHeaderMalformed { .. }
 			| Error::InvalidBase64(_)
 			| Error::InvalidUtf8Str(_)
 			| Error::InvalidDigest(_)
diff --git a/src/api/s3/error.rs b/src/api/s3/error.rs
index 74ef6692..09aa0604 100644
--- a/src/api/s3/error.rs
+++ b/src/api/s3/error.rs
@@ -31,8 +31,13 @@ pub enum Error {
 
 	// Category: cannot process
 	/// Authorization Header Malformed
-	#[error("Authorization header malformed, unexpected scope: {0}")]
-	AuthorizationHeaderMalformed(String),
+	#[error(
+		"Authorization header malformed, unexpected scope: '{unexpected}', expected: '{expected}'"
+	)]
+	AuthorizationHeaderMalformed {
+		unexpected: String,
+		expected: String,
+	},
 
 	/// The object requested don't exists
 	#[error("Key not found")]
@@ -121,9 +126,13 @@ impl From<SignatureError> for Error {
 	fn from(err: SignatureError) -> Self {
 		match err {
 			SignatureError::Common(c) => Self::Common(c),
-			SignatureError::AuthorizationHeaderMalformed(c) => {
-				Self::AuthorizationHeaderMalformed(c)
-			}
+			SignatureError::AuthorizationHeaderMalformed {
+				unexpected,
+				expected,
+			} => Self::AuthorizationHeaderMalformed {
+				unexpected,
+				expected,
+			},
 			SignatureError::InvalidUtf8Str(i) => Self::InvalidUtf8Str(i),
 			SignatureError::InvalidDigest(d) => Self::InvalidDigest(d),
 		}
@@ -146,7 +155,7 @@ impl Error {
 			Error::InvalidPart => "InvalidPart",
 			Error::InvalidPartOrder => "InvalidPartOrder",
 			Error::EntityTooSmall => "EntityTooSmall",
-			Error::AuthorizationHeaderMalformed(_) => "AuthorizationHeaderMalformed",
+			Error::AuthorizationHeaderMalformed { .. } => "AuthorizationHeaderMalformed",
 			Error::InvalidXml(_) => "MalformedXML",
 			Error::InvalidXmlDe(_) => "MalformedXML",
 			Error::InvalidXmlSe(_) => "InternalError",
@@ -172,7 +181,7 @@ impl ApiError for Error {
 			Error::PreconditionFailed => StatusCode::PRECONDITION_FAILED,
 			Error::InvalidRange(_) => StatusCode::RANGE_NOT_SATISFIABLE,
 			Error::InvalidXmlSe(_) => StatusCode::INTERNAL_SERVER_ERROR,
-			Error::AuthorizationHeaderMalformed(_)
+			Error::AuthorizationHeaderMalformed { .. }
 			| Error::InvalidPart
 			| Error::InvalidPartOrder
 			| Error::EntityTooSmall