diff --git a/changelog.md b/changelog.md
index 7c0ec1c9..e87737fc 100644
--- a/changelog.md
+++ b/changelog.md
@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Fix: forgot to update model CI build to follow new src layout (@lwasser, #438)
+- Fix: Type annotation on field that are of type timedelta are now correct (@enadeau, #440)
 
 ## v1.5
 
diff --git a/src/stravalib/field_conversions.py b/src/stravalib/field_conversions.py
index 630a9a5a..51ab7066 100644
--- a/src/stravalib/field_conversions.py
+++ b/src/stravalib/field_conversions.py
@@ -2,7 +2,6 @@
 
 import logging
 from collections.abc import Sequence
-from datetime import timedelta
 from functools import wraps
 from typing import Callable, TypeVar
 
@@ -55,14 +54,6 @@ def enum_values(enums: Sequence[ActivityType | SportType]) -> list[str | None]:
     return [enum_value(e) for e in enums]
 
 
-@optional_input
-def time_interval(seconds: int) -> timedelta:
-    """
-    Replaces legacy TimeIntervalAttribute
-    """
-    return timedelta(seconds=seconds)
-
-
 @optional_input
 def timezone(
     tz: str,
diff --git a/src/stravalib/model.py b/src/stravalib/model.py
index 498c5f9f..07560236 100644
--- a/src/stravalib/model.py
+++ b/src/stravalib/model.py
@@ -13,7 +13,7 @@
 from __future__ import annotations
 
 import logging
-from datetime import date, datetime
+from datetime import date, datetime, timedelta
 from functools import wraps
 from typing import (
     TYPE_CHECKING,
@@ -36,7 +36,6 @@
 from stravalib.field_conversions import (
     enum_value,
     enum_values,
-    time_interval,
     timezone,
 )
 from stravalib.strava_model import (
@@ -492,11 +491,11 @@ class ActivityTotals(
     elapsed time, moving time, distance and elevation gain."""
 
     _field_conversions = {
-        "elapsed_time": time_interval,
-        "moving_time": time_interval,
         "distance": uh.meters,
         "elevation_gain": uh.meters,
     }
+    elapsed_time: Optional[timedelta] = None  # type: ignore[assignment]
+    moving_time: Optional[timedelta] = None  # type: ignore[assignment]
 
 
 class AthleteStats(
@@ -785,13 +784,13 @@ class ActivityLap(
     device_watts: Optional[bool] = None
 
     _field_conversions = {
-        "elapsed_time": time_interval,
-        "moving_time": time_interval,
         "distance": uh.meters,
         "total_elevation_gain": uh.meters,
         "average_speed": uh.meters_per_second,
         "max_speed": uh.meters_per_second,
     }
+    elapsed_time: Optional[timedelta] = None  # type: ignore[assignment]
+    moving_time: Optional[timedelta] = None  # type: ignore[assignment]
 
     _naive_local = validator("start_date_local", allow_reuse=True)(
         naive_datetime
@@ -819,13 +818,13 @@ class Split(
     average_grade_adjusted_speed: Optional[float] = None
 
     _field_conversions = {
-        "elapsed_time": time_interval,
-        "moving_time": time_interval,
         "distance": uh.meters,
         "elevation_difference": uh.meters,
         "average_speed": uh.meters_per_second,
         "average_grade_adjusted_speed": uh.meters_per_second,
     }
+    elapsed_time: Optional[timedelta] = None  # type: ignore[assignment]
+    moving_time: Optional[timedelta] = None  # type: ignore[assignment]
 
 
 class SegmentExplorerResult(
@@ -882,14 +881,13 @@ class AthleteSegmentStats(
 
     # Undocumented attributes:
     effort_count: Optional[int] = None
-    pr_elapsed_time: Optional[int] = None
+    pr_elapsed_time: Optional[timedelta] = None
     pr_date: Optional[date] = None
 
     _field_conversions = {
-        "elapsed_time": time_interval,
-        "pr_elapsed_time": time_interval,
         "distance": uh.meters,
     }
+    elapsed_time: Optional[timedelta] = None  # type: ignore[assignment]
 
     _naive_local = validator("start_date_local", allow_reuse=True)(
         naive_datetime
@@ -908,16 +906,16 @@ class AthletePrEffort(
     is_kom: Optional[bool] = None
 
     _field_conversions = {
-        "pr_elapsed_time": time_interval,
         "distance": uh.meters,
     }
+    pr_elapsed_time: Optional[timedelta] = None  # type: ignore[assignment]
 
     _naive_local = validator("start_date_local", allow_reuse=True)(
         naive_datetime
     )
 
     @property
-    def elapsed_time(self) -> Optional[int]:
+    def elapsed_time(self) -> Optional[timedelta]:
         # For backward compatibility
         return self.pr_elapsed_time
 
@@ -946,7 +944,7 @@ class Segment(
     start_longitude: Optional[float] = None
     end_longitude: Optional[float] = None
     starred: Optional[bool] = None
-    pr_time: Optional[int] = None
+    pr_time: Optional[timedelta] = None
     starred_date: Optional[datetime] = None
     elevation_profile: Optional[str] = None
 
@@ -955,7 +953,6 @@ class Segment(
         "elevation_high": uh.meters,
         "elevation_low": uh.meters,
         "total_elevation_gain": uh.meters,
-        "pr_time": time_interval,
     }
 
     _latlng_check = validator(
@@ -1002,10 +999,10 @@ class BaseEffort(
     athlete: Optional[Athlete] = None
 
     _field_conversions = {
-        "moving_time": time_interval,
-        "elapsed_time": time_interval,
         "distance": uh.meters,
     }
+    moving_time: Optional[timedelta] = None  # type: ignore[assignment]
+    elapsed_time: Optional[timedelta] = None  # type: ignore[assignment]
 
     _naive_local = validator("start_date_local", allow_reuse=True)(
         naive_datetime
@@ -1086,8 +1083,6 @@ class Activity(
     perceived_exertion: Optional[int] = None
 
     _field_conversions = {
-        "moving_time": time_interval,
-        "elapsed_time": time_interval,
         "timezone": timezone,
         "distance": uh.meters,
         "total_elevation_gain": uh.meters,
@@ -1096,6 +1091,8 @@ class Activity(
         "type": enum_value,
         "sport_type": enum_value,
     }
+    moving_time: Optional[timedelta] = None  # type: ignore[assignment]
+    elapsed_time: Optional[timedelta] = None  # type: ignore[assignment]
 
     _latlng_check = validator(
         "start_latlng", "end_latlng", allow_reuse=True, pre=True