         guard let oauthVerifier = decoder
             .decodeObject(of: NSString.self,
                           forKey: NSCodingKeys.oauthVerifier) as String? else {
-            let error = CocoaError.error(.coderValueNotFound)
-            decoder.failWithError(error)
+            if #available(iOS 9, *) {
+                    let error = CocoaError.error(.coderValueNotFound)
+                    decoder.failWithError(error)
+            }
             return nil
         }
         self.oauthVerifier = oauthVerifier

        guard let oauthTokenSecret = decoder
            .decodeObject(of: NSString.self,
                          forKey: NSCodingKeys.oauthTokenSecret) as String? else {
            let error = CocoaError.error(.coderValueNotFound)
            decoder.failWithError(error)
            return nil
        }
        self.oauthTokenSecret = oauthTokenSecret

        guard let oauthRefreshToken = decoder
            .decodeObject(of: NSString.self,
                          forKey: NSCodingKeys.oauthRefreshToken) as String? else {
            if #available(iOS 9, *) {
                let error = CocoaError.error(.coderValueNotFound)
                decoder.failWithError(error)
            }
            return nil
        }
        self.oauthRefreshToken = oauthRefreshToken
