diff --git a/README.md b/README.md
index df43957f..27918db5 100644
--- a/README.md
+++ b/README.md
@@ -1339,7 +1339,7 @@ CustomRoute(
   page: LoginRoute.page,
   // TransitionsBuilders class contains a preset of common transitions builders.
   transitionsBuilder: TransitionsBuilders.slideBottom,
-  durationInMilliseconds: 400,
+  duration: Duration(milliseconds: 400),
 )
 ```
 
diff --git a/auto_route/lib/src/route/auto_route_config.dart b/auto_route/lib/src/route/auto_route_config.dart
index 33593fdf..b90f6e48 100644
--- a/auto_route/lib/src/route/auto_route_config.dart
+++ b/auto_route/lib/src/route/auto_route_config.dart
@@ -390,8 +390,8 @@ class CustomRoute<R> extends AutoRoute {
     super.allowSnapshotting = true,
     RouteTransitionsBuilder? transitionsBuilder,
     CustomRouteBuilder? customRouteBuilder,
-    int? durationInMilliseconds,
-    int? reverseDurationInMilliseconds,
+    Duration? duration,
+    Duration? reverseDuration,
     bool opaque = true,
     bool barrierDismissible = true,
     String? barrierLabel,
@@ -401,8 +401,8 @@ class CustomRoute<R> extends AutoRoute {
           type: RouteType.custom(
             transitionsBuilder: transitionsBuilder,
             customRouteBuilder: customRouteBuilder,
-            durationInMilliseconds: durationInMilliseconds,
-            reverseDurationInMilliseconds: reverseDurationInMilliseconds,
+            duration: duration,
+            reverseDuration: reverseDuration,
             opaque: opaque,
             barrierDismissible: barrierDismissible,
             barrierLabel: barrierLabel,
diff --git a/auto_route/lib/src/route/route_type.dart b/auto_route/lib/src/route/route_type.dart
index 834651a2..411e02ce 100644
--- a/auto_route/lib/src/route/route_type.dart
+++ b/auto_route/lib/src/route/route_type.dart
@@ -41,8 +41,8 @@ abstract class RouteType {
   const factory RouteType.custom({
     RouteTransitionsBuilder? transitionsBuilder,
     CustomRouteBuilder? customRouteBuilder,
-    int? durationInMilliseconds,
-    int? reverseDurationInMilliseconds,
+    Duration? duration,
+    Duration? reverseDuration,
     bool opaque,
     bool barrierDismissible,
     String? barrierLabel,
@@ -110,15 +110,15 @@ class CustomRouteType extends RouteType {
   ///  },
   final CustomRouteBuilder? customRouteBuilder;
 
-  /// route transition duration in milliseconds
+  /// route transition duration
   /// is passed to [PageRouteBuilder]
   /// this property is ignored unless a [transitionBuilder] is provided
-  final int? durationInMilliseconds;
+  final Duration? duration;
 
-  /// route reverse transition duration in milliseconds
+  /// route reverse transition duration
   /// is passed to [PageRouteBuilder]
   /// this property is ignored unless a [transitionBuilder] is provided
-  final int? reverseDurationInMilliseconds;
+  final Duration? reverseDuration;
 
   /// passed to the barrierDismissible property in [PageRouteBuilder]
   ///
@@ -141,8 +141,8 @@ class CustomRouteType extends RouteType {
     this.barrierLabel,
     this.barrierColor,
     this.transitionsBuilder,
-    this.durationInMilliseconds,
-    this.reverseDurationInMilliseconds,
+    this.duration,
+    this.reverseDuration,
     super.opaque,
     this.barrierDismissible = false,
   }) : super._();
@@ -155,9 +155,8 @@ class CustomRouteType extends RouteType {
           runtimeType == other.runtimeType &&
           transitionsBuilder == other.transitionsBuilder &&
           customRouteBuilder == other.customRouteBuilder &&
-          durationInMilliseconds == other.durationInMilliseconds &&
-          reverseDurationInMilliseconds ==
-              other.reverseDurationInMilliseconds &&
+          duration == other.duration &&
+          reverseDuration == other.reverseDuration &&
           barrierDismissible == other.barrierDismissible &&
           barrierLabel == other.barrierLabel &&
           barrierColor == other.barrierColor;
@@ -167,8 +166,8 @@ class CustomRouteType extends RouteType {
       super.hashCode ^
       transitionsBuilder.hashCode ^
       customRouteBuilder.hashCode ^
-      durationInMilliseconds.hashCode ^
-      reverseDurationInMilliseconds.hashCode ^
+      duration.hashCode ^
+      reverseDuration.hashCode ^
       barrierDismissible.hashCode ^
       barrierLabel.hashCode ^
       barrierColor.hashCode;
diff --git a/auto_route/lib/src/router/auto_route_page.dart b/auto_route/lib/src/router/auto_route_page.dart
index 76551030..d6d1f971 100644
--- a/auto_route/lib/src/router/auto_route_page.dart
+++ b/auto_route/lib/src/router/auto_route_page.dart
@@ -271,14 +271,12 @@ mixin _CustomPageRouteTransitionMixin<T> on PageRoute<T> {
   Widget buildContent(BuildContext context);
 
   @override
-  Duration get transitionDuration => Duration(
-        milliseconds: routeType.durationInMilliseconds ?? 300,
-      );
+  Duration get transitionDuration =>
+      routeType.duration ?? const Duration(milliseconds: 300);
 
   @override
-  Duration get reverseTransitionDuration => Duration(
-        milliseconds: routeType.reverseDurationInMilliseconds ?? 300,
-      );
+  Duration get reverseTransitionDuration =>
+      routeType.reverseDuration ?? const Duration(milliseconds: 300);
 
   @override
   bool get barrierDismissible => routeType.barrierDismissible;