diff --git a/Lombiq.VueJs.Samples/Controllers/QrCardController.cs b/Lombiq.VueJs.Samples/Controllers/QrCardController.cs
index 910f519..6904f7f 100644
--- a/Lombiq.VueJs.Samples/Controllers/QrCardController.cs
+++ b/Lombiq.VueJs.Samples/Controllers/QrCardController.cs
@@ -34,8 +34,12 @@ public ActionResult Index()
         });
     }
 
-    public async Task<ActionResult> GetBusinessCard(string cardId) =>
-        await _contentManager.GetAsync(cardId) is { } businessCard
+    public async Task<ActionResult> GetBusinessCard(string cardId)
+    {
+        if (!ModelState.IsValid) return BadRequest(ModelState);
+
+        return await _contentManager.GetAsync(cardId) is { } businessCard
             ? Ok(businessCard)
             : NotFound();
+    }
 }
diff --git a/Lombiq.VueJs.Samples/Controllers/VueSfcController.cs b/Lombiq.VueJs.Samples/Controllers/VueSfcController.cs
index adaf67c..f5214bf 100644
--- a/Lombiq.VueJs.Samples/Controllers/VueSfcController.cs
+++ b/Lombiq.VueJs.Samples/Controllers/VueSfcController.cs
@@ -35,15 +35,18 @@ public VueSfcController(IClock clock, IStringLocalizer<VueSfcController> stringL
     // Here we show off a way of doing progressive enhancement. This first action has everything you need to access the
     // page without JS.
     // Open this from under /Lombiq.VueJs.Samples/VueSfc/EnhancedList
-    public ActionResult EnhancedList(int page = 1) => View(new EnhancedListViewModel
-    {
-        Page = page,
-        Data = GetDataForPage(page),
-    });
+    public ActionResult EnhancedList(int page = 1) =>
+        ModelState.IsValid
+        ? View(new EnhancedListViewModel
+        {
+            Page = page,
+            Data = GetDataForPage(page),
+        })
+        : BadRequest(ModelState);
 
     // This method returns JSON, providing an API equivalent for the EnhancedList action. The enhanced app will use that
     // to update results asynchronously. Both use the same source of data.
-    public ActionResult GetList(int page = 1) => Json(GetDataForPage(page));
+    public ActionResult GetList(int page = 1) => ModelState.IsValid ? Json(GetDataForPage(page)) : BadRequest(ModelState);
 
     // What is in this method isn't really important, just some sample data to show change.
     [SuppressMessage("Security", "CA5394:Do not use insecure randomness", Justification = "It's not security critical.")]
diff --git a/Lombiq.VueJs/Services/IVueSingleFileComponentShapeAmender.cs b/Lombiq.VueJs/Services/IVueSingleFileComponentShapeAmender.cs
index 5a8b6c3..bee4a7a 100644
--- a/Lombiq.VueJs/Services/IVueSingleFileComponentShapeAmender.cs
+++ b/Lombiq.VueJs/Services/IVueSingleFileComponentShapeAmender.cs
@@ -1,6 +1,5 @@
 using Microsoft.AspNetCore.Html;
 using System.Collections.Generic;
-using System.Linq;
 using System.Threading.Tasks;
 
 namespace Lombiq.VueJs.Services;
@@ -14,11 +13,11 @@ public interface IVueSingleFileComponentShapeAmender
     /// Lets you prepend content to the Vue.js template outputted by the shape. The <paramref name="shapeName"/> is
     /// provided to help limit the scope, but you can also ignore it to amend every Vue.js shape.
     /// </summary>
-    ValueTask<IEnumerable<IHtmlContent>> PrependAsync(string shapeName) => new(Enumerable.Empty<IHtmlContent>());
+    ValueTask<IEnumerable<IHtmlContent>> PrependAsync(string shapeName) => new([]);
 
     /// <summary>
     /// Lets you append content to the Vue.js template outputted by the shape. The <paramref name="shapeName"/> is
     /// provided to help limit the scope, but you can also ignore it to amend every Vue.js shape.
     /// </summary>
-    ValueTask<IEnumerable<IHtmlContent>> AppendAsync(string shapeName) => new(Enumerable.Empty<IHtmlContent>());
+    ValueTask<IEnumerable<IHtmlContent>> AppendAsync(string shapeName) => new([]);
 }
diff --git a/Lombiq.VueJs/Services/ServerSideValuesVueSingleFileComponentShapeAmenderBase.cs b/Lombiq.VueJs/Services/ServerSideValuesVueSingleFileComponentShapeAmenderBase.cs
index 18403a3..8d4fbdb 100644
--- a/Lombiq.VueJs/Services/ServerSideValuesVueSingleFileComponentShapeAmenderBase.cs
+++ b/Lombiq.VueJs/Services/ServerSideValuesVueSingleFileComponentShapeAmenderBase.cs
@@ -2,7 +2,6 @@
 using Newtonsoft.Json;
 using Newtonsoft.Json.Serialization;
 using System.Collections.Generic;
-using System.Linq;
 using System.Threading.Tasks;
 
 namespace Lombiq.VueJs.Services;
@@ -38,7 +37,7 @@ public abstract class ServerSideValuesVueSingleFileComponentShapeAmenderBase : I
     /// </summary>
     public async ValueTask<IEnumerable<IHtmlContent>> PrependAsync(string shapeName)
     {
-        if (ShapeName != null && ShapeName != shapeName) return Enumerable.Empty<IHtmlContent>();
+        if (ShapeName != null && ShapeName != shapeName) return [];
 
         var values = await GetPropertyValueAsync(shapeName);
         var json = JsonConvert.SerializeObject(
@@ -46,14 +45,14 @@ public async ValueTask<IEnumerable<IHtmlContent>> PrependAsync(string shapeName)
             Formatting.None,
             new JsonSerializerSettings { ContractResolver = new CamelCasePropertyNamesContractResolver() });
 
-        return new[]
-        {
+        return
+        [
             new HtmlString(
                 "<script>" +
                 "if (!window.Vue.$orchardCore) window.Vue.$orchardCore = {};" +
                 $"window.Vue.$orchardCore[{JsonConvert.SerializeObject(PropertyName)}] = {json};" +
                 "</script>"),
-        };
+        ];
     }
 
     /// <summary>
diff --git a/Lombiq.VueJs/Services/VueComponentContentSecurityPolicyProvider.cs b/Lombiq.VueJs/Services/VueComponentContentSecurityPolicyProvider.cs
index 2e850cb..95c6d83 100644
--- a/Lombiq.VueJs/Services/VueComponentContentSecurityPolicyProvider.cs
+++ b/Lombiq.VueJs/Services/VueComponentContentSecurityPolicyProvider.cs
@@ -24,7 +24,7 @@ public ValueTask UpdateAsync(IDictionary<string, string> securityPolicies, HttpC
     {
         if (_state.Active)
         {
-            ContentSecurityPolicyProvider.MergeDirectiveValues(securityPolicies, new[] { ScriptSrc }, UnsafeEval);
+            ContentSecurityPolicyProvider.MergeDirectiveValues(securityPolicies, [ScriptSrc], UnsafeEval);
         }
 
         return ValueTask.CompletedTask;
diff --git a/Lombiq.VueJs/Services/VueSingleFileComponentShapeTemplateViewEngine.cs b/Lombiq.VueJs/Services/VueSingleFileComponentShapeTemplateViewEngine.cs
index 90fc690..a1ab6e8 100644
--- a/Lombiq.VueJs/Services/VueSingleFileComponentShapeTemplateViewEngine.cs
+++ b/Lombiq.VueJs/Services/VueSingleFileComponentShapeTemplateViewEngine.cs
@@ -27,7 +27,7 @@ public class VueSingleFileComponentShapeTemplateViewEngine : IShapeTemplateViewE
     private readonly IEnumerable<IVueSingleFileComponentShapeAmender> _amenders;
     private readonly IEnumerable<IVueTemplateExpressionConverter> _converters;
 
-    public IEnumerable<string> TemplateFileExtensions { get; } = new[] { ".vue" };
+    public IEnumerable<string> TemplateFileExtensions { get; } = [".vue"];
 
     public VueSingleFileComponentShapeTemplateViewEngine(
         IShapeTemplateFileProviderAccessor fileProviderAccessor,
diff --git a/Lombiq.VueJs/Services/VueSingleFileComponentTemplateHarvester.cs b/Lombiq.VueJs/Services/VueSingleFileComponentTemplateHarvester.cs
index 0c4c927..0218b59 100644
--- a/Lombiq.VueJs/Services/VueSingleFileComponentTemplateHarvester.cs
+++ b/Lombiq.VueJs/Services/VueSingleFileComponentTemplateHarvester.cs
@@ -2,7 +2,6 @@
 using OrchardCore.Mvc.Utilities;
 using System;
 using System.Collections.Generic;
-using System.Linq;
 
 namespace Lombiq.VueJs.Services;
 
@@ -10,16 +9,16 @@ public class VueSingleFileComponentTemplateHarvester : IShapeTemplateHarvester
 {
     private const string SubPath = "Assets/Scripts/VueComponents";
 
-    public IEnumerable<string> SubPaths() => new[] { SubPath };
+    public IEnumerable<string> SubPaths() => [SubPath];
 
     public IEnumerable<HarvestShapeHit> HarvestShape(HarvestShapeInfo info) =>
         !info.SubPath.StartsWith(SubPath, StringComparison.OrdinalIgnoreCase)
-            ? Enumerable.Empty<HarvestShapeHit>()
-            : new[]
-            {
+            ? []
+            :
+            [
                 new HarvestShapeHit
                 {
                     ShapeType = "VueComponent-" + info.FileName.ToPascalCaseDash(),
                 },
-            };
+            ];
 }