diff --git a/bibtex_linter/ieeetr_rules.py b/bibtex_linter/ieeetr_rules.py
index 0b8203d..cc974f7 100644
--- a/bibtex_linter/ieeetr_rules.py
+++ b/bibtex_linter/ieeetr_rules.py
@@ -26,7 +26,6 @@ def check_article(entry: BibTeXEntry) -> List[str]:
     }
     omitted_fields: Set[str] = {
         "language",
-        "number",
         "url",
     }
     invariant_violations.extend(check_required_fields(entry, required_fields))