diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/ISO8601.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/ISO8601.cpp
index 0b9fcd4a87..bbaad1ab39 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/ISO8601.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/ISO8601.cpp
@@ -875,7 +875,7 @@ bool ISO8601Parser::parse_temporal_calendar_string()
     //     DateSpecYearMonth
     //     DateSpecMonthDay
     return parse_calendar_name()
-        // TODO: || parse_temporal_instant_string()
+        || parse_temporal_instant_string()
         || parse_calendar_date_time()
         || parse_date_spec_year_month()
         || parse_date_spec_month_day()