diff --git a/packages/go_router_builder/CHANGELOG.md b/packages/go_router_builder/CHANGELOG.md
index 344e81a2339..1ba9a69dbaf 100644
--- a/packages/go_router_builder/CHANGELOG.md
+++ b/packages/go_router_builder/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 3.3.1
+
+- Fixes warnings in generated code of iterable parameters.
+
 ## 3.3.0
 
 - Adds support for `TypedRelativeGoRoute`.
diff --git a/packages/go_router_builder/example/lib/all_types.g.dart b/packages/go_router_builder/example/lib/all_types.g.dart
index e9aa673fc5c..99fa26729fd 100644
--- a/packages/go_router_builder/example/lib/all_types.g.dart
+++ b/packages/go_router_builder/example/lib/all_types.g.dart
@@ -92,8 +92,9 @@ mixin _$AllTypesBaseRoute on GoRouteData {
 
 mixin _$BigIntRoute on GoRouteData {
   static BigIntRoute _fromState(GoRouterState state) => BigIntRoute(
-    requiredBigIntField:
-        BigInt.parse(state.pathParameters['requiredBigIntField']!)!,
+    requiredBigIntField: BigInt.parse(
+      state.pathParameters['requiredBigIntField']!,
+    ),
     bigIntField: _$convertMapValue(
       'big-int-field',
       state.uri.queryParameters,
@@ -128,8 +129,9 @@ mixin _$BigIntRoute on GoRouteData {
 
 mixin _$BoolRoute on GoRouteData {
   static BoolRoute _fromState(GoRouterState state) => BoolRoute(
-    requiredBoolField:
-        _$boolConverter(state.pathParameters['requiredBoolField']!)!,
+    requiredBoolField: _$boolConverter(
+      state.pathParameters['requiredBoolField']!,
+    ),
     boolField: _$convertMapValue(
       'bool-field',
       state.uri.queryParameters,
@@ -173,8 +175,9 @@ mixin _$BoolRoute on GoRouteData {
 
 mixin _$DateTimeRoute on GoRouteData {
   static DateTimeRoute _fromState(GoRouterState state) => DateTimeRoute(
-    requiredDateTimeField:
-        DateTime.parse(state.pathParameters['requiredDateTimeField']!)!,
+    requiredDateTimeField: DateTime.parse(
+      state.pathParameters['requiredDateTimeField']!,
+    ),
     dateTimeField: _$convertMapValue(
       'date-time-field',
       state.uri.queryParameters,
@@ -209,8 +212,9 @@ mixin _$DateTimeRoute on GoRouteData {
 
 mixin _$DoubleRoute on GoRouteData {
   static DoubleRoute _fromState(GoRouterState state) => DoubleRoute(
-    requiredDoubleField:
-        double.parse(state.pathParameters['requiredDoubleField']!)!,
+    requiredDoubleField: double.parse(
+      state.pathParameters['requiredDoubleField']!,
+    ),
     doubleField: _$convertMapValue(
       'double-field',
       state.uri.queryParameters,
@@ -255,7 +259,7 @@ mixin _$DoubleRoute on GoRouteData {
 
 mixin _$IntRoute on GoRouteData {
   static IntRoute _fromState(GoRouterState state) => IntRoute(
-    requiredIntField: int.parse(state.pathParameters['requiredIntField']!)!,
+    requiredIntField: int.parse(state.pathParameters['requiredIntField']!),
     intField: _$convertMapValue(
       'int-field',
       state.uri.queryParameters,
@@ -299,7 +303,7 @@ mixin _$IntRoute on GoRouteData {
 
 mixin _$NumRoute on GoRouteData {
   static NumRoute _fromState(GoRouterState state) => NumRoute(
-    requiredNumField: num.parse(state.pathParameters['requiredNumField']!)!,
+    requiredNumField: num.parse(state.pathParameters['requiredNumField']!),
     numField: _$convertMapValue(
       'num-field',
       state.uri.queryParameters,
@@ -487,7 +491,7 @@ mixin _$StringRoute on GoRouteData {
 
 mixin _$UriRoute on GoRouteData {
   static UriRoute _fromState(GoRouterState state) => UriRoute(
-    requiredUriField: Uri.parse(state.pathParameters['requiredUriField']!)!,
+    requiredUriField: Uri.parse(state.pathParameters['requiredUriField']!),
     uriField: _$convertMapValue(
       'uri-field',
       state.uri.queryParameters,
@@ -522,110 +526,83 @@ mixin _$UriRoute on GoRouteData {
 mixin _$IterableRoute on GoRouteData {
   static IterableRoute _fromState(GoRouterState state) => IterableRoute(
     intIterableField:
-        (state.uri.queryParametersAll['int-iterable-field']
-                ?.map(int.parse)
-                .cast<int>()
-            as Iterable<int>?),
+        state.uri.queryParametersAll['int-iterable-field']
+            ?.map(int.parse)
+            .cast<int>(),
     doubleIterableField:
-        (state.uri.queryParametersAll['double-iterable-field']
-                ?.map(double.parse)
-                .cast<double>()
-            as Iterable<double>?),
-    stringIterableField: (state.uri.queryParametersAll['string-iterable-field']
-        ?.map((e) => e)),
+        state.uri.queryParametersAll['double-iterable-field']
+            ?.map(double.parse)
+            .cast<double>(),
+    stringIterableField: state.uri.queryParametersAll['string-iterable-field']
+        ?.map((e) => e),
     boolIterableField:
-        (state.uri.queryParametersAll['bool-iterable-field']
-                ?.map(_$boolConverter)
-                .cast<bool>()
-            as Iterable<bool>?),
+        state.uri.queryParametersAll['bool-iterable-field']
+            ?.map(_$boolConverter)
+            .cast<bool>(),
     enumIterableField:
-        (state.uri.queryParametersAll['enum-iterable-field']
-                ?.map(_$SportDetailsEnumMap._$fromName)
-                .cast<SportDetails>()
-            as Iterable<SportDetails>?),
+        state.uri.queryParametersAll['enum-iterable-field']
+            ?.map(_$SportDetailsEnumMap._$fromName)
+            .cast<SportDetails>(),
     enumOnlyInIterableField:
-        (state.uri.queryParametersAll['enum-only-in-iterable-field']
-                ?.map(_$CookingRecipeEnumMap._$fromName)
-                .cast<CookingRecipe>()
-            as Iterable<CookingRecipe>?),
+        state.uri.queryParametersAll['enum-only-in-iterable-field']
+            ?.map(_$CookingRecipeEnumMap._$fromName)
+            .cast<CookingRecipe>(),
     intListField:
-        (state.uri.queryParametersAll['int-list-field']
-                    ?.map(int.parse)
-                    .cast<int>()
-                    ?.toList()
-                as List<int>?)
-            ?.toList(),
+        state.uri.queryParametersAll['int-list-field']
+            ?.map(int.parse)
+            .cast<int>()
+            .toList(),
     doubleListField:
-        (state.uri.queryParametersAll['double-list-field']
-                    ?.map(double.parse)
-                    .cast<double>()
-                    ?.toList()
-                as List<double>?)
-            ?.toList(),
+        state.uri.queryParametersAll['double-list-field']
+            ?.map(double.parse)
+            .cast<double>()
+            .toList(),
     stringListField:
-        (state.uri.queryParametersAll['string-list-field']?.map(
-          (e) => e,
-        ))?.toList(),
+        state.uri.queryParametersAll['string-list-field']
+            ?.map((e) => e)
+            .toList(),
     boolListField:
-        (state.uri.queryParametersAll['bool-list-field']
-                    ?.map(_$boolConverter)
-                    .cast<bool>()
-                    ?.toList()
-                as List<bool>?)
-            ?.toList(),
+        state.uri.queryParametersAll['bool-list-field']
+            ?.map(_$boolConverter)
+            .cast<bool>()
+            .toList(),
     enumListField:
-        (state.uri.queryParametersAll['enum-list-field']
-                    ?.map(_$SportDetailsEnumMap._$fromName)
-                    .cast<SportDetails>()
-                    ?.toList()
-                as List<SportDetails>?)
-            ?.toList(),
+        state.uri.queryParametersAll['enum-list-field']
+            ?.map(_$SportDetailsEnumMap._$fromName)
+            .cast<SportDetails>()
+            .toList(),
     enumOnlyInListField:
-        (state.uri.queryParametersAll['enum-only-in-list-field']
-                    ?.map(_$CookingRecipeEnumMap._$fromName)
-                    .cast<CookingRecipe>()
-                    ?.toList()
-                as List<CookingRecipe>?)
-            ?.toList(),
+        state.uri.queryParametersAll['enum-only-in-list-field']
+            ?.map(_$CookingRecipeEnumMap._$fromName)
+            .cast<CookingRecipe>()
+            .toList(),
     intSetField:
-        (state.uri.queryParametersAll['int-set-field']
-                    ?.map(int.parse)
-                    .cast<int>()
-                    ?.toSet()
-                as Set<int>?)
-            ?.toSet(),
+        state.uri.queryParametersAll['int-set-field']
+            ?.map(int.parse)
+            .cast<int>()
+            .toSet(),
     doubleSetField:
-        (state.uri.queryParametersAll['double-set-field']
-                    ?.map(double.parse)
-                    .cast<double>()
-                    ?.toSet()
-                as Set<double>?)
-            ?.toSet(),
+        state.uri.queryParametersAll['double-set-field']
+            ?.map(double.parse)
+            .cast<double>()
+            .toSet(),
     stringSetField:
-        (state.uri.queryParametersAll['string-set-field']?.map(
-          (e) => e,
-        ))?.toSet(),
+        state.uri.queryParametersAll['string-set-field']?.map((e) => e).toSet(),
     boolSetField:
-        (state.uri.queryParametersAll['bool-set-field']
-                    ?.map(_$boolConverter)
-                    .cast<bool>()
-                    ?.toSet()
-                as Set<bool>?)
-            ?.toSet(),
+        state.uri.queryParametersAll['bool-set-field']
+            ?.map(_$boolConverter)
+            .cast<bool>()
+            .toSet(),
     enumSetField:
-        (state.uri.queryParametersAll['enum-set-field']
-                    ?.map(_$SportDetailsEnumMap._$fromName)
-                    .cast<SportDetails>()
-                    ?.toSet()
-                as Set<SportDetails>?)
-            ?.toSet(),
+        state.uri.queryParametersAll['enum-set-field']
+            ?.map(_$SportDetailsEnumMap._$fromName)
+            .cast<SportDetails>()
+            .toSet(),
     enumOnlyInSetField:
-        (state.uri.queryParametersAll['enum-only-in-set-field']
-                    ?.map(_$CookingRecipeEnumMap._$fromName)
-                    .cast<CookingRecipe>()
-                    ?.toSet()
-                as Set<CookingRecipe>?)
-            ?.toSet(),
+        state.uri.queryParametersAll['enum-only-in-set-field']
+            ?.map(_$CookingRecipeEnumMap._$fromName)
+            .cast<CookingRecipe>()
+            .toSet(),
   );
 
   IterableRoute get _self => this as IterableRoute;
@@ -718,107 +695,87 @@ mixin _$IterableRouteWithDefaultValues on GoRouteData {
   static IterableRouteWithDefaultValues _fromState(GoRouterState state) =>
       IterableRouteWithDefaultValues(
         intIterableField:
-            (state.uri.queryParametersAll['int-iterable-field']
-                    ?.map(int.parse)
-                    .cast<int>()
-                as Iterable<int>?) ??
+            state.uri.queryParametersAll['int-iterable-field']
+                ?.map(int.parse)
+                .cast<int>() ??
             const <int>[0],
         doubleIterableField:
-            (state.uri.queryParametersAll['double-iterable-field']
-                    ?.map(double.parse)
-                    .cast<double>()
-                as Iterable<double>?) ??
+            state.uri.queryParametersAll['double-iterable-field']
+                ?.map(double.parse)
+                .cast<double>() ??
             const <double>[0, 1, 2],
         stringIterableField:
-            (state.uri.queryParametersAll['string-iterable-field']?.map(
+            state.uri.queryParametersAll['string-iterable-field']?.map(
               (e) => e,
-            )) ??
+            ) ??
             const <String>['defaultValue'],
         boolIterableField:
-            (state.uri.queryParametersAll['bool-iterable-field']
-                    ?.map(_$boolConverter)
-                    .cast<bool>()
-                as Iterable<bool>?) ??
+            state.uri.queryParametersAll['bool-iterable-field']
+                ?.map(_$boolConverter)
+                .cast<bool>() ??
             const <bool>[false],
         enumIterableField:
-            (state.uri.queryParametersAll['enum-iterable-field']
-                    ?.map(_$SportDetailsEnumMap._$fromName)
-                    .cast<SportDetails>()
-                as Iterable<SportDetails>?) ??
+            state.uri.queryParametersAll['enum-iterable-field']
+                ?.map(_$SportDetailsEnumMap._$fromName)
+                .cast<SportDetails>() ??
             const <SportDetails>[SportDetails.tennis, SportDetails.hockey],
         intListField:
-            (state.uri.queryParametersAll['int-list-field']
-                        ?.map(int.parse)
-                        .cast<int>()
-                        ?.toList()
-                    as List<int>?)
-                ?.toList() ??
+            state.uri.queryParametersAll['int-list-field']
+                ?.map(int.parse)
+                .cast<int>()
+                .toList() ??
             const <int>[0],
         doubleListField:
-            (state.uri.queryParametersAll['double-list-field']
-                        ?.map(double.parse)
-                        .cast<double>()
-                        ?.toList()
-                    as List<double>?)
-                ?.toList() ??
+            state.uri.queryParametersAll['double-list-field']
+                ?.map(double.parse)
+                .cast<double>()
+                .toList() ??
             const <double>[1, 2, 3],
         stringListField:
-            (state.uri.queryParametersAll['string-list-field']?.map(
-              (e) => e,
-            ))?.toList() ??
+            state.uri.queryParametersAll['string-list-field']
+                ?.map((e) => e)
+                .toList() ??
             const <String>['defaultValue0', 'defaultValue1'],
         boolListField:
-            (state.uri.queryParametersAll['bool-list-field']
-                        ?.map(_$boolConverter)
-                        .cast<bool>()
-                        ?.toList()
-                    as List<bool>?)
-                ?.toList() ??
+            state.uri.queryParametersAll['bool-list-field']
+                ?.map(_$boolConverter)
+                .cast<bool>()
+                .toList() ??
             const <bool>[true],
         enumListField:
-            (state.uri.queryParametersAll['enum-list-field']
-                        ?.map(_$SportDetailsEnumMap._$fromName)
-                        .cast<SportDetails>()
-                        ?.toList()
-                    as List<SportDetails>?)
-                ?.toList() ??
+            state.uri.queryParametersAll['enum-list-field']
+                ?.map(_$SportDetailsEnumMap._$fromName)
+                .cast<SportDetails>()
+                .toList() ??
             const <SportDetails>[SportDetails.football],
         intSetField:
-            (state.uri.queryParametersAll['int-set-field']
-                        ?.map(int.parse)
-                        .cast<int>()
-                        ?.toSet()
-                    as Set<int>?)
-                ?.toSet() ??
+            state.uri.queryParametersAll['int-set-field']
+                ?.map(int.parse)
+                .cast<int>()
+                .toSet() ??
             const <int>{0, 1},
         doubleSetField:
-            (state.uri.queryParametersAll['double-set-field']
-                        ?.map(double.parse)
-                        .cast<double>()
-                        ?.toSet()
-                    as Set<double>?)
-                ?.toSet() ??
+            state.uri.queryParametersAll['double-set-field']
+                ?.map(double.parse)
+                .cast<double>()
+                .toSet() ??
             const <double>{},
         stringSetField:
-            (state.uri.queryParametersAll['string-set-field']?.map(
-              (e) => e,
-            ))?.toSet() ??
+            state.uri.queryParametersAll['string-set-field']
+                ?.map((e) => e)
+                .toSet() ??
             const <String>{'defaultValue'},
         boolSetField:
-            (state.uri.queryParametersAll['bool-set-field']
-                        ?.map(_$boolConverter)
-                        .cast<bool>()
-                        ?.toSet()
-                    as Set<bool>?)
-                ?.toSet() ??
+            state.uri.queryParametersAll['bool-set-field']
+                ?.map(_$boolConverter)
+                .cast<bool>()
+                .toSet() ??
             const <bool>{true, false},
         enumSetField:
-            (state.uri.queryParametersAll['enum-set-field']
-                        ?.map(_$SportDetailsEnumMap._$fromName)
-                        .cast<SportDetails>()
-                        ?.toSet()
-                    as Set<SportDetails>?)
-                ?.toSet() ??
+            state.uri.queryParametersAll['enum-set-field']
+                ?.map(_$SportDetailsEnumMap._$fromName)
+                .cast<SportDetails>()
+                .toSet() ??
             const <SportDetails>{SportDetails.hockey},
       );
 
diff --git a/packages/go_router_builder/example/lib/main.g.dart b/packages/go_router_builder/example/lib/main.g.dart
index 99786802ebf..e5d10a26fb2 100644
--- a/packages/go_router_builder/example/lib/main.g.dart
+++ b/packages/go_router_builder/example/lib/main.g.dart
@@ -84,7 +84,7 @@ mixin _$FamilyRoute on GoRouteData {
 mixin _$PersonRoute on GoRouteData {
   static PersonRoute _fromState(GoRouterState state) => PersonRoute(
     state.pathParameters['fid']!,
-    int.parse(state.pathParameters['pid']!)!,
+    int.parse(state.pathParameters['pid']!),
   );
 
   PersonRoute get _self => this as PersonRoute;
@@ -112,7 +112,7 @@ mixin _$PersonDetailsRoute on GoRouteData {
   static PersonDetailsRoute _fromState(GoRouterState state) =>
       PersonDetailsRoute(
         state.pathParameters['fid']!,
-        int.parse(state.pathParameters['pid']!)!,
+        int.parse(state.pathParameters['pid']!),
         _$PersonDetailsEnumMap._$fromName(state.pathParameters['details']!)!,
         $extra: state.extra as int?,
       );
@@ -148,7 +148,7 @@ const _$PersonDetailsEnumMap = {
 
 mixin _$FamilyCountRoute on GoRouteData {
   static FamilyCountRoute _fromState(GoRouterState state) =>
-      FamilyCountRoute(int.parse(state.pathParameters['count']!)!);
+      FamilyCountRoute(int.parse(state.pathParameters['count']!));
 
   FamilyCountRoute get _self => this as FamilyCountRoute;
 
diff --git a/packages/go_router_builder/example/lib/readme_excerpts.g.dart b/packages/go_router_builder/example/lib/readme_excerpts.g.dart
index 878f8027153..9b7225f7eb9 100644
--- a/packages/go_router_builder/example/lib/readme_excerpts.g.dart
+++ b/packages/go_router_builder/example/lib/readme_excerpts.g.dart
@@ -174,7 +174,7 @@ RouteBase get $hotdogRouteWithEverything => GoRouteData.$route(
 mixin _$HotdogRouteWithEverything on GoRouteData {
   static HotdogRouteWithEverything _fromState(GoRouterState state) =>
       HotdogRouteWithEverything(
-        _$boolConverter(state.pathParameters['ketchup']!)!,
+        _$boolConverter(state.pathParameters['ketchup']!),
         state.uri.queryParameters['mustard'],
         state.extra as Sauce,
       );
diff --git a/packages/go_router_builder/example/lib/shell_route_with_keys_example.g.dart b/packages/go_router_builder/example/lib/shell_route_with_keys_example.g.dart
index b3cb84bd5b8..3687993d37b 100644
--- a/packages/go_router_builder/example/lib/shell_route_with_keys_example.g.dart
+++ b/packages/go_router_builder/example/lib/shell_route_with_keys_example.g.dart
@@ -77,7 +77,7 @@ mixin _$UsersRouteData on GoRouteData {
 
 mixin _$UserRouteData on GoRouteData {
   static UserRouteData _fromState(GoRouterState state) =>
-      UserRouteData(id: int.parse(state.pathParameters['id']!)!);
+      UserRouteData(id: int.parse(state.pathParameters['id']!));
 
   UserRouteData get _self => this as UserRouteData;
 
diff --git a/packages/go_router_builder/example/lib/shell_route_with_observers_example.g.dart b/packages/go_router_builder/example/lib/shell_route_with_observers_example.g.dart
index caa853af7a1..88d3b84b9a6 100644
--- a/packages/go_router_builder/example/lib/shell_route_with_observers_example.g.dart
+++ b/packages/go_router_builder/example/lib/shell_route_with_observers_example.g.dart
@@ -73,7 +73,7 @@ mixin _$UsersRouteData on GoRouteData {
 
 mixin _$UserRouteData on GoRouteData {
   static UserRouteData _fromState(GoRouterState state) =>
-      UserRouteData(id: int.parse(state.pathParameters['id']!)!);
+      UserRouteData(id: int.parse(state.pathParameters['id']!));
 
   UserRouteData get _self => this as UserRouteData;
 
diff --git a/packages/go_router_builder/lib/src/type_helpers.dart b/packages/go_router_builder/lib/src/type_helpers.dart
index 6741e21ad4f..294e1d325dd 100644
--- a/packages/go_router_builder/lib/src/type_helpers.dart
+++ b/packages/go_router_builder/lib/src/type_helpers.dart
@@ -468,24 +468,12 @@ class _TypeHelperIterable extends _TypeHelperWithHelper {
       // get a type converter for values in iterable
       String entriesTypeDecoder = '(e) => e';
       String convertToNotNull = '';
-      String formatIterableType = '';
-      String asParameterType = ' as ${parameterElement.type}';
-
-      if (parameterElement.hasDefaultValue) {
-        asParameterType += '?';
-      }
 
       for (final _TypeHelper helper in _helpers) {
         if (helper._matchesType(iterableType) &&
             helper is _TypeHelperWithHelper) {
           if (!iterableType.isNullableType) {
-            if (parameterElement.type.isDartCoreList) {
-              formatIterableType = '?.toList()';
-            } else if (parameterElement.type.isDartCoreSet) {
-              formatIterableType = '?.toSet()';
-            }
-            convertToNotNull =
-                '.cast<$iterableType>()$formatIterableType$asParameterType';
+            convertToNotNull = '.cast<$iterableType>()';
           }
           entriesTypeDecoder = helper.helperName(iterableType);
         }
@@ -497,7 +485,7 @@ class _TypeHelperIterable extends _TypeHelperWithHelper {
       if (const TypeChecker.fromRuntime(
         List,
       ).isAssignableFromType(parameterElement.type)) {
-        iterableCaster += '?.toList()';
+        iterableCaster += '.toList()';
         if (!parameterElement.type.isNullableType &&
             !parameterElement.hasDefaultValue) {
           fallBack = '?? const []';
@@ -505,7 +493,7 @@ class _TypeHelperIterable extends _TypeHelperWithHelper {
       } else if (const TypeChecker.fromRuntime(
         Set,
       ).isAssignableFromType(parameterElement.type)) {
-        iterableCaster += '?.toSet()';
+        iterableCaster += '.toSet()';
         if (!parameterElement.type.isNullableType &&
             !parameterElement.hasDefaultValue) {
           fallBack = '?? const {}';
@@ -513,9 +501,9 @@ class _TypeHelperIterable extends _TypeHelperWithHelper {
       }
 
       return '''
-(state.uri.queryParametersAll[
+state.uri.queryParametersAll[
         ${escapeDartString(parameterElement.displayName.kebab)}]
-        ?.map($entriesTypeDecoder)$convertToNotNull)$iterableCaster$fallBack''';
+        ?.map($entriesTypeDecoder)$convertToNotNull$iterableCaster$fallBack''';
     }
     return '''
 state.uri.queryParametersAll[${escapeDartString(parameterElement.displayName.kebab)}]''';
@@ -572,14 +560,21 @@ abstract class _TypeHelperWithHelper extends _TypeHelper {
           'state.uri.queryParameters, '
           '${helperName(paramType)})';
     }
+
+    final String nullableSuffix =
+        paramType.isNullableType ||
+                (paramType.isEnum && !paramType.isNullableType)
+            ? '!'
+            : '';
+
     return '${helperName(paramType)}'
-        '(state.${_stateValueAccess(parameterElement, pathParameters)} ${!parameterElement.isRequired ? " ?? '' " : ''})!';
+        '(state.${_stateValueAccess(parameterElement, pathParameters)} ${!parameterElement.isRequired ? " ?? '' " : ''})$nullableSuffix';
   }
 }
 
 /// Extension helpers on [DartType].
 extension DartTypeExtension on DartType {
-  /// Convenient helper for nullability checks.
+  /// Convenient helper for nullability checks.parameterElement.isRequired
   String get ensureNotNull => isNullableType ? '!' : '';
 }
 
diff --git a/packages/go_router_builder/pubspec.yaml b/packages/go_router_builder/pubspec.yaml
index 801facafad4..cfcb00adbde 100644
--- a/packages/go_router_builder/pubspec.yaml
+++ b/packages/go_router_builder/pubspec.yaml
@@ -2,7 +2,7 @@ name: go_router_builder
 description: >-
   A builder that supports generated strongly-typed route helpers for
   package:go_router
-version: 3.3.0
+version: 3.3.1
 repository: https://github.com/flutter/packages/tree/main/packages/go_router_builder
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+go_router_builder%22
 
@@ -23,7 +23,7 @@ dependencies:
 
 dev_dependencies:
   build_test: ^3.3.0
-  dart_style: '>=2.3.7 <4.0.0'
+  dart_style: ">=2.3.7 <4.0.0"
   flutter:
     sdk: flutter
   go_router: ^16.2.0
diff --git a/packages/go_router_builder/test_inputs/iterable_with_default_value.dart.expect b/packages/go_router_builder/test_inputs/iterable_with_default_value.dart.expect
index 35e4cb75fb5..dfec9129769 100644
--- a/packages/go_router_builder/test_inputs/iterable_with_default_value.dart.expect
+++ b/packages/go_router_builder/test_inputs/iterable_with_default_value.dart.expect
@@ -6,10 +6,9 @@ RouteBase get $iterableDefaultValueRoute => GoRouteData.$route(
 mixin _$IterableDefaultValueRoute on GoRouteData {
   static IterableDefaultValueRoute _fromState(GoRouterState state) =>
       IterableDefaultValueRoute(
-        param: (state.uri.queryParametersAll['param']
-                ?.map(int.parse)
-                .cast<int>() as Iterable<int>?) ??
-            const <int>[0],
+        param:
+            state.uri.queryParametersAll['param']?.map(int.parse).cast<int>() ??
+                const <int>[0],
       );
 
   IterableDefaultValueRoute get _self => this as IterableDefaultValueRoute;
diff --git a/packages/go_router_builder/test_inputs/iterable_with_enum.dart.expect b/packages/go_router_builder/test_inputs/iterable_with_enum.dart.expect
index ef7fd9fec7c..185e61cbd65 100644
--- a/packages/go_router_builder/test_inputs/iterable_with_enum.dart.expect
+++ b/packages/go_router_builder/test_inputs/iterable_with_enum.dart.expect
@@ -6,10 +6,9 @@ RouteBase get $iterableWithEnumRoute => GoRouteData.$route(
 mixin _$IterableWithEnumRoute on GoRouteData {
   static IterableWithEnumRoute _fromState(GoRouterState state) =>
       IterableWithEnumRoute(
-        param: (state.uri.queryParametersAll['param']
-                ?.map(_$EnumOnlyUsedInIterableEnumMap._$fromName)
-                .cast<EnumOnlyUsedInIterable>()
-            as Iterable<EnumOnlyUsedInIterable>?),
+        param: state.uri.queryParametersAll['param']
+            ?.map(_$EnumOnlyUsedInIterableEnumMap._$fromName)
+            .cast<EnumOnlyUsedInIterable>(),
       );
 
   IterableWithEnumRoute get _self => this as IterableWithEnumRoute;
diff --git a/packages/go_router_builder/test_inputs/list.dart.expect b/packages/go_router_builder/test_inputs/list.dart.expect
index abe23c4c4f1..f3c39bbea0b 100644
--- a/packages/go_router_builder/test_inputs/list.dart.expect
+++ b/packages/go_router_builder/test_inputs/list.dart.expect
@@ -5,23 +5,20 @@ RouteBase get $listRoute => GoRouteData.$route(
 
 mixin _$ListRoute on GoRouteData {
   static ListRoute _fromState(GoRouterState state) => ListRoute(
-        ids: (state.uri.queryParametersAll['ids']
-                    ?.map(int.parse)
-                    .cast<int>()
-                    ?.toList() as List<int>)
-                ?.toList() ??
+        ids: state.uri.queryParametersAll['ids']
+                ?.map(int.parse)
+                .cast<int>()
+                .toList() ??
             const [],
-        nullableIds: (state.uri.queryParametersAll['nullable-ids']
+        nullableIds: state.uri.queryParametersAll['nullable-ids']
+            ?.map(int.parse)
+            .cast<int>()
+            .toList(),
+        idsWithDefaultValue: state
+                .uri.queryParametersAll['ids-with-default-value']
                 ?.map(int.parse)
                 .cast<int>()
-                ?.toList() as List<int>?)
-            ?.toList(),
-        idsWithDefaultValue: (state
-                    .uri.queryParametersAll['ids-with-default-value']
-                    ?.map(int.parse)
-                    .cast<int>()
-                    ?.toList() as List<int>?)
-                ?.toList() ??
+                .toList() ??
             const <int>[0],
       );
 
diff --git a/packages/go_router_builder/test_inputs/parameter_generates_a_warning.dart b/packages/go_router_builder/test_inputs/parameter_generates_a_warning.dart
new file mode 100644
index 00000000000..18081cdfd1a
--- /dev/null
+++ b/packages/go_router_builder/test_inputs/parameter_generates_a_warning.dart
@@ -0,0 +1,14 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:go_router/go_router.dart';
+
+@TypedGoRoute<MyRoute>(path: '/product/:id')
+class MyRoute extends GoRouteData with _$MyRoute {
+  const MyRoute(this.id);
+  final int id;
+}
+
+// avoid error when run analytic
+mixin _$MyRoute {}
diff --git a/packages/go_router_builder/test_inputs/parameter_generates_a_warning.dart.expect b/packages/go_router_builder/test_inputs/parameter_generates_a_warning.dart.expect
new file mode 100644
index 00000000000..ea0ba9d2c99
--- /dev/null
+++ b/packages/go_router_builder/test_inputs/parameter_generates_a_warning.dart.expect
@@ -0,0 +1,30 @@
+RouteBase get $myRoute => GoRouteData.$route(
+      path: '/product/:id',
+      factory: _$MyRoute._fromState,
+    );
+
+mixin _$MyRoute on GoRouteData {
+  static MyRoute _fromState(GoRouterState state) => MyRoute(
+        int.parse(state.pathParameters['id']!),
+      );
+
+  MyRoute get _self => this as MyRoute;
+
+  @override
+  String get location => GoRouteData.$location(
+        '/product/${Uri.encodeComponent(_self.id.toString())}',
+      );
+
+  @override
+  void go(BuildContext context) => context.go(location);
+
+  @override
+  Future<T?> push<T>(BuildContext context) => context.push<T>(location);
+
+  @override
+  void pushReplacement(BuildContext context) =>
+      context.pushReplacement(location);
+
+  @override
+  void replace(BuildContext context) => context.replace(location);
+}
\ No newline at end of file
diff --git a/packages/go_router_builder/test_inputs/required_query_parameter.dart.expect b/packages/go_router_builder/test_inputs/required_query_parameter.dart.expect
index 23487d96d6e..1aa70667195 100644
--- a/packages/go_router_builder/test_inputs/required_query_parameter.dart.expect
+++ b/packages/go_router_builder/test_inputs/required_query_parameter.dart.expect
@@ -6,7 +6,7 @@ RouteBase get $nonNullableRequiredParamNotInPath => GoRouteData.$route(
 mixin _$NonNullableRequiredParamNotInPath on GoRouteData {
   static NonNullableRequiredParamNotInPath _fromState(GoRouterState state) =>
       NonNullableRequiredParamNotInPath(
-        id: int.parse(state.uri.queryParameters['id']!)!,
+        id: int.parse(state.uri.queryParameters['id']!),
       );
 
   NonNullableRequiredParamNotInPath get _self =>
diff --git a/packages/go_router_builder/test_inputs/set.dart.expect b/packages/go_router_builder/test_inputs/set.dart.expect
index 69d25393d59..a8decd72730 100644
--- a/packages/go_router_builder/test_inputs/set.dart.expect
+++ b/packages/go_router_builder/test_inputs/set.dart.expect
@@ -5,23 +5,20 @@ RouteBase get $setRoute => GoRouteData.$route(
 
 mixin _$SetRoute on GoRouteData {
   static SetRoute _fromState(GoRouterState state) => SetRoute(
-        ids: (state.uri.queryParametersAll['ids']
-                    ?.map(int.parse)
-                    .cast<int>()
-                    ?.toSet() as Set<int>)
-                ?.toSet() ??
+        ids: state.uri.queryParametersAll['ids']
+                ?.map(int.parse)
+                .cast<int>()
+                .toSet() ??
             const {},
-        nullableIds: (state.uri.queryParametersAll['nullable-ids']
+        nullableIds: state.uri.queryParametersAll['nullable-ids']
+            ?.map(int.parse)
+            .cast<int>()
+            .toSet(),
+        idsWithDefaultValue: state
+                .uri.queryParametersAll['ids-with-default-value']
                 ?.map(int.parse)
                 .cast<int>()
-                ?.toSet() as Set<int>?)
-            ?.toSet(),
-        idsWithDefaultValue: (state
-                    .uri.queryParametersAll['ids-with-default-value']
-                    ?.map(int.parse)
-                    .cast<int>()
-                    ?.toSet() as Set<int>?)
-                ?.toSet() ??
+                .toSet() ??
             const <int>{0},
       );