diff --git a/src/digimarks/main.py b/src/digimarks/main.py
index 534657e..940abba 100644
--- a/src/digimarks/main.py
+++ b/src/digimarks/main.py
@@ -275,12 +275,24 @@ async def bookmarks_changed_since(
     )
     latest_created_bookmark = result.first()
 
-    latest_modification = max(latest_modified_bookmark.modified_date, latest_created_bookmark.created_date)
+    # There needs to be at least one bookmark of course
+    if latest_created_bookmark:
+        latest_created_datetime = latest_created_bookmark.created_date
+    else:
+        latest_created_datetime = datetime.min
+
+    # We only have a modified datetime when at least one has been edited
+    if latest_modified_bookmark:
+        latest_modified_datetime = latest_modified_bookmark.modified_date
+    else:
+        latest_modified_datetime = datetime.min
+
+    latest_modification = max(latest_modified_datetime, latest_created_datetime)
 
     return {
         'current_time': datetime.now(UTC),
-        'latest_change': latest_modified_bookmark.modified_date,
-        'latest_created': latest_created_bookmark.created_date,
+        'latest_change': latest_modified_datetime,
+        'latest_created': latest_created_datetime,
         'latest_modification': latest_modification,
     }