diff --git a/aider_gitea/__main__.py b/aider_gitea/__main__.py
index c7f9bb6..3d1b6ac 100644
--- a/aider_gitea/__main__.py
+++ b/aider_gitea/__main__.py
@@ -25,7 +25,7 @@ def generate_branch_name(issue_number: str, issue_title: str) -> str:
     the text is lowercased, and spaces are replaced with dashes.
     """
     sanitized = re.sub(r"[^0-9a-zA-Z ]+", "", issue_title)
-    parts = ['issue', issue_number, *sanitized.lower().split()]
+    parts = ['issue', str(issue_number), *sanitized.lower().split()]
     return "-".join(parts)
 
 logger = logging.getLogger(__name__)