diff --git a/src/errors.rs b/src/errors.rs
index 0559d3c..104fee8 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -37,6 +37,8 @@ pub enum Error {
     Client(StatusCode),
     /// Generic server error.
     Server(StatusCode),
+    /// MastodonBuilder error.
+    DataMissing,
 }
 
 impl fmt::Display for Error {
@@ -63,6 +65,7 @@ impl error::Error for Error {
             Error::ClientIdRequired => "ClientIdRequired",
             Error::ClientSecretRequired => "ClientSecretRequired",
             Error::AccessTokenRequired => "AccessTokenRequired",
+            Error::DataMissing => "DataMissing",
         }
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index 05af459..5beca56 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -438,6 +438,7 @@ impl MastodonBuilder {
         }
     }
 
+    #[allow(dead_code)]
     pub fn client(&mut self, client: Client) -> &mut Self {
         self.client = Some(client);
         self