diff --git a/MailKit/Net/Imap/ImapCommand.cs b/MailKit/Net/Imap/ImapCommand.cs
index f3e7d64ce6..a029ce0873 100644
--- a/MailKit/Net/Imap/ImapCommand.cs
+++ b/MailKit/Net/Imap/ImapCommand.cs
@@ -907,7 +907,7 @@ public async Task<bool> StepAsync (bool doAsync)
 					if (token.Type != ImapTokenType.Eoln) {
 						// consume the rest of the line...
 						var line = (await Engine.ReadLineAsync (doAsync, CancellationToken).ConfigureAwait (false)).TrimEnd ();
-						ResponseText = ((string) token.Value) + line;
+						ResponseText = token.Value.ToString () + line;
 						break;
 					}
 				} else if (token.Type == ImapTokenType.OpenBracket) {
diff --git a/MailKit/Net/Imap/ImapEngine.cs b/MailKit/Net/Imap/ImapEngine.cs
index 38f2bcdb09..e46b11c0cd 100644
--- a/MailKit/Net/Imap/ImapEngine.cs
+++ b/MailKit/Net/Imap/ImapEngine.cs
@@ -675,7 +675,7 @@ public async Task ConnectAsync (ImapStream stream, bool doAsync, CancellationTok
 					}
 				} else if (token.Type != ImapTokenType.Eoln) {
 					text = (await ReadLineAsync (doAsync, cancellationToken).ConfigureAwait (false)).TrimEnd ();
-					text = ((string) token.Value) + text;
+					text = token.Value.ToString () + text;
 
 					if (bye)
 						throw new ImapProtocolException (text);
@@ -2045,7 +2045,7 @@ internal async Task<ImapUntaggedResult> ProcessUntaggedResponseAsync (bool doAsy
 					current.RespCodes.Add (code);
 				} else {
 					var text = (await ReadLineAsync (doAsync, cancellationToken).ConfigureAwait (false)).TrimEnd ();
-					current.ResponseText = ((string) token.Value) + text;
+					current.ResponseText = token.Value.ToString () + text;
 				}
 
 				current.Bye = true;
@@ -2097,7 +2097,7 @@ internal async Task<ImapUntaggedResult> ProcessUntaggedResponseAsync (bool doAsy
 					current.RespCodes.Add (code);
 				} else if (token.Type != ImapTokenType.Eoln) {
 					var text = (await ReadLineAsync (doAsync, cancellationToken).ConfigureAwait (false)).TrimEnd ();
-					current.ResponseText = ((string) token.Value) + text;
+					current.ResponseText = token.Value.ToString () + text;
 				}
 			} else {
 				if (uint.TryParse (atom, NumberStyles.None, CultureInfo.InvariantCulture, out uint number)) {