diff --git a/CHANGELOG.md b/CHANGELOG.md
index c3f0476..fb7e4bd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@
 as `text` instead of `long` (Closes issue #31)
 - Bugfix: IDLE email processing in Gmail/G-Suite accounts (closes issue #33)
 - Bugfix: Fix inaccurate DNS timeout in CLI documentation (closes issue #34)
+- Bugfix: Crash when `Arrival-Date` header is missing in a 
+forensic/fialure/ruf report 
 - IMAP reliability improvements
 - Save data in separate indexes each day to make managing data retention easier
 - Cache DNS queries in memory
diff --git a/parsedmarc/__init__.py b/parsedmarc/__init__.py
index f30aa07..19108ae 100644
--- a/parsedmarc/__init__.py
+++ b/parsedmarc/__init__.py
@@ -527,7 +527,7 @@ def parse_forensic_report(feedback_report, sample, msg_date,
             parsed_report[key] = report_value[1]
 
         if "arrival_date" not in parsed_report:
-            parsed_report["arrival_date"] = msg_date
+            parsed_report["arrival_date"] = msg_date.isoformat()
 
         if "version" not in parsed_report:
             parsed_report["version"] = 1