diff --git a/src/YouTrackSharp/Issues/IssuesService.Attachments.cs b/src/YouTrackSharp/Issues/IssuesService.Attachments.cs
index b1fa1ea..4b4afbc 100644
--- a/src/YouTrackSharp/Issues/IssuesService.Attachments.cs
+++ b/src/YouTrackSharp/Issues/IssuesService.Attachments.cs
@@ -37,7 +37,7 @@ public async Task AttachFileToIssue(string issueId, string attachmentName, Strea
             {
                 queryString.Add($"group={group}");
             }
-            if (!string.IsNullOrEmpty(group))
+            if (!string.IsNullOrEmpty(author))
             {
                 queryString.Add($"author={author}");
             }