syncf.diff

diff --git a/src/web/error.rs b/src/web/error.rs
index c6035be0..0f855ebd 100644
--- a/src/web/error.rs
+++ b/src/web/error.rs
@@ -4,7 +4,7 @@ use std::fmt;
 
 use actix_web::http::header::ToStrError;
 use base64::DecodeError;
-use failure::{Backtrace, Context, Fail};
+use failure::{Backtrace, Context, Fail, SyncFailure};
 use hawk::Error as ParseError;
 use hmac::crypto_mac::{InvalidKeyLength, MacError};
 use serde_json::Error as JsonError;
@@ -54,7 +54,7 @@ pub enum HawkErrorKind {
     MissingPrefix,
 
     #[fail(display = "{}", _0)]
-    Parse(ParseError),
+    Parse(SyncFailure<ParseError>),
 
     #[fail(display = "id property is too short")]
     TruncatedId,
@@ -67,7 +67,12 @@ from_error!(InvalidKeyLength, ApiError, HawkErrorKind::InvalidKeyLength);
 from_error!(JsonError, ApiError, HawkErrorKind::Json);
 from_error!(MacError, ApiError, HawkErrorKind::Hmac);
 from_error!(ToStrError, ApiError, HawkErrorKind::Header);
-from_error!(ParseError, ApiError, HawkErrorKind::Parse);
+
+impl From<ParseError> for ApiError {
+    fn from(inner: ParseError) -> ApiError {
+        HawkErrorKind::Parse(SyncFailure::new(inner)).into()
+    }
+}
 
 impl From<HawkErrorKind> for ApiError {
     fn from(kind: HawkErrorKind) -> Self {
@@ -75,5 +80,3 @@ impl From<HawkErrorKind> for ApiError {
         hawk_error.into()
     }
 }
-
-unsafe impl Sync for HawkErrorKind {}