diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,6 +3,5 @@
 # dependency lines, see https://pip.readthedocs.org/en/1.1/requirements.html
 click
 iso8601
-python-dateutil
 subvertpy >= 0.9.4
 typing-extensions
diff --git a/swh/loader/svn/converters.py b/swh/loader/svn/converters.py
--- a/swh/loader/svn/converters.py
+++ b/swh/loader/svn/converters.py
@@ -6,17 +6,17 @@
 import datetime
 from typing import Dict, Optional, Sequence, Tuple
 
-import dateutil
+import iso8601
 
 from swh.model.model import Person, Revision, RevisionType, TimestampWithTimezone
 
 
-def svn_date_to_swh_date(strdate: Optional[str]) -> TimestampWithTimezone:
+def svn_date_to_swh_date(strdate: Optional[bytes]) -> TimestampWithTimezone:
     """Convert a string date to an swh one.
 
     Args:
         strdate: A string representing a date with format like
-        'YYYY-mm-DDTHH:MM:SS.800722Z'
+        ``b'YYYY-mm-DDTHH:MM:SS.800722Z'``
 
     Returns:
         An swh date format
@@ -25,8 +25,7 @@
     if not strdate:  # either None or empty string
         dt = datetime.datetime(1970, 1, 1, tzinfo=datetime.timezone.utc)
     else:
-        # TODO: Migrate to iso8601 if possible
-        dt = dateutil.parser.parse(strdate)
+        dt = iso8601.parse_date(strdate.decode("ascii"))
         assert dt.tzinfo is not None, strdate
     return TimestampWithTimezone.from_datetime(dt)
 
diff --git a/swh/loader/svn/svn.py b/swh/loader/svn/svn.py
--- a/swh/loader/svn/svn.py
+++ b/swh/loader/svn/svn.py
@@ -110,7 +110,7 @@
             return msg
         return msg.encode("utf-8")
 
-    def convert_commit_date(self, date: str) -> TimestampWithTimezone:
+    def convert_commit_date(self, date: bytes) -> TimestampWithTimezone:
         """Convert the message commit date into a timestamp in swh format.
         The precision is kept.
 
diff --git a/swh/loader/svn/tests/test_converters.py b/swh/loader/svn/tests/test_converters.py
--- a/swh/loader/svn/tests/test_converters.py
+++ b/swh/loader/svn/tests/test_converters.py
@@ -97,7 +97,7 @@
 
     """
     assert converters.svn_date_to_swh_date(
-        "2011-05-31T06:04:39.500900Z"
+        b"2011-05-31T06:04:39.500900Z"
     ) == TimestampWithTimezone(
         timestamp=Timestamp(seconds=1306821879, microseconds=500900),
         offset=0,
@@ -105,7 +105,7 @@
     )
 
     assert converters.svn_date_to_swh_date(
-        "2011-05-31T06:04:39.800722Z"
+        b"2011-05-31T06:04:39.800722Z"
     ) == TimestampWithTimezone(
         timestamp=Timestamp(seconds=1306821879, microseconds=800722),
         offset=0,