diff --git a/src/lib.rs b/src/lib.rs
index 7088f77..631d5bb 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -39,11 +39,22 @@ enum Error {
 impl StdError for Error {}
 
 #[cfg(target_os = "macos")]
+#[derive(Debug)]
 enum MacOsError {
     AppErr(ApplicationError),
     NotErr(NotificationError),
 }
 
+#[cfg(target_os = "macos")]
+impl Display for MacOsError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            MacOsError::AppErr(e) => Display::fmt(e, f),
+            MacOsError::NotErr(e) => Display::fmt(e, f),
+        }
+    }
+}
+
 impl Display for Error {
     fn fmt(&self, fmt: &mut Formatter) -> Result<(), fmt::Error> {
         match self {