diff --git a/Iceshrimp.Backend/Core/Extensions/MvcBuilderExtensions.cs b/Iceshrimp.Backend/Core/Extensions/MvcBuilderExtensions.cs
index 5d3bea3a..2c53bdaa 100644
--- a/Iceshrimp.Backend/Core/Extensions/MvcBuilderExtensions.cs
+++ b/Iceshrimp.Backend/Core/Extensions/MvcBuilderExtensions.cs
@@ -1,6 +1,9 @@
 using System.Buffers;
+using System.Net;
 using System.Text.Encodings.Web;
+using System.Text.Json;
 using Iceshrimp.Backend.Controllers.Attributes;
+using Iceshrimp.Backend.Core.Middleware;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.Formatters;
 using Microsoft.AspNetCore.Mvc.ModelBinding;
@@ -55,4 +58,25 @@ public static class MvcBuilderExtensions
 
 		return builder;
 	}
+
+	public static IMvcBuilder AddApiBehaviorOptions(this IMvcBuilder builder)
+	{
+		builder.ConfigureApiBehaviorOptions(o =>
+		{
+			o.InvalidModelStateResponseFactory = actionContext =>
+			{
+				var details = new ValidationProblemDetails(actionContext.ModelState);
+
+				var status  = (HttpStatusCode?)details.Status ?? HttpStatusCode.BadRequest;
+				var message = details.Title ?? "One or more validation errors occurred.";
+				if (details.Detail != null)
+					message += $" - {details.Detail}";
+				var errors = JsonSerializer.Serialize(details.Errors);
+
+				throw new GracefulException(status, status.ToString(), message, errors);
+			};
+		});
+
+		return builder;
+	}
 }
\ No newline at end of file
diff --git a/Iceshrimp.Backend/Startup.cs b/Iceshrimp.Backend/Startup.cs
index b684a995..e6d2bd40 100644
--- a/Iceshrimp.Backend/Startup.cs
+++ b/Iceshrimp.Backend/Startup.cs
@@ -11,7 +11,8 @@ builder.Services.AddControllers()
        .AddNewtonsoftJson() //TODO: remove once dotNetRdf switches to System.Text.Json (or we switch to LinkedData.NET)
        .AddMultiFormatter()
        .AddModelBindingProviders()
-       .AddValueProviderFactories();
+       .AddValueProviderFactories()
+       .AddApiBehaviorOptions();
 
 builder.Services.AddSwaggerGenWithOptions();
 builder.Services.AddLogging(logging => logging.AddCustomConsoleFormatter());