diff --git a/fimfarchive/converters/local_utc.py b/fimfarchive/converters/local_utc.py
index d1b4eab..2e580e8 100644
--- a/fimfarchive/converters/local_utc.py
+++ b/fimfarchive/converters/local_utc.py
@@ -50,7 +50,7 @@ class DateNormalizer(JayWalker):
         """
         parsed = arrow.get(value or 0)
 
-        if parsed.timestamp == 0:
+        if parsed.int_timestamp == 0:
             return None
 
         return parsed.to('utc').isoformat()
diff --git a/tests/test_mappers.py b/tests/test_mappers.py
index 2a1caa9..7c62bec 100644
--- a/tests/test_mappers.py
+++ b/tests/test_mappers.py
@@ -138,7 +138,7 @@ class TestStoryDateMapper:
 
         story = story.merge(meta=meta)
 
-        assert mapper(story).timestamp == 5
+        assert mapper(story).int_timestamp == 5
 
     def test_meta_with_none_chapters(self, mapper, story):
         """
@@ -151,7 +151,7 @@ class TestStoryDateMapper:
 
         story = story.merge(meta=meta)
 
-        assert mapper(story).timestamp == 5
+        assert mapper(story).int_timestamp == 5
 
     def test_meta_with_empty_chapters(self, mapper, story):
         """
@@ -164,7 +164,7 @@ class TestStoryDateMapper:
 
         story = story.merge(meta=meta)
 
-        assert mapper(story).timestamp == 5
+        assert mapper(story).int_timestamp == 5
 
     def test_meta_with_only_chapter_dates(self, mapper, story):
         """
@@ -180,7 +180,7 @@ class TestStoryDateMapper:
 
         story = story.merge(meta=meta)
 
-        assert mapper(story).timestamp == 5
+        assert mapper(story).int_timestamp == 5
 
     def test_meta_with_only_story_date(self, mapper, story):
         """
@@ -197,7 +197,7 @@ class TestStoryDateMapper:
 
         story = story.merge(meta=meta)
 
-        assert mapper(story).timestamp == 5
+        assert mapper(story).int_timestamp == 5
 
     def test_meta_with_latest_chapter_date(self, mapper, story):
         """
@@ -214,7 +214,7 @@ class TestStoryDateMapper:
 
         story = story.merge(meta=meta)
 
-        assert mapper(story).timestamp == 5
+        assert mapper(story).int_timestamp == 5
 
     def test_meta_with_latest_story_date(self, mapper, story):
         """
@@ -231,7 +231,7 @@ class TestStoryDateMapper:
 
         story = story.merge(meta=meta)
 
-        assert mapper(story).timestamp == 5
+        assert mapper(story).int_timestamp == 5
 
     def test_meta_with_both_latest(self, mapper, story):
         """
@@ -248,7 +248,7 @@ class TestStoryDateMapper:
 
         story = story.merge(meta=meta)
 
-        assert mapper(story).timestamp == 5
+        assert mapper(story).int_timestamp == 5
 
 
 class TestStoryPathMapper: