diff --git a/src/Registration/Registration.API/RequestModels/ParticipantRegistrationRequest.cs b/src/Registration/Registration.API/RequestModels/ParticipantRegistrationRequest.cs
index f8a6fdb..18ac30c 100644
--- a/src/Registration/Registration.API/RequestModels/ParticipantRegistrationRequest.cs
+++ b/src/Registration/Registration.API/RequestModels/ParticipantRegistrationRequest.cs
@@ -20,8 +20,8 @@ public class ParticipantRegistrationRequest
     public string SurName { get; set; } = string.Empty;
 
     [Required]
-    [RegularExpression(@"^([1-9]|1[1-3])$",
-        ErrorMessage = "Årkurs måste vara 1–9 eller 11–13.")]
+    [RegularExpression(@"^([1-9]|1[0-2])$",
+        ErrorMessage = "Årkurs måste vara 1–9 eller 10–12.")]
     public string Grade { get; set; } = string.Empty;
 
     public string? PhoneNumber { get; set; }
diff --git a/src/Web/lan-frontend/app/register/page.tsx b/src/Web/lan-frontend/app/register/page.tsx
index 21675d8..b71440c 100644
--- a/src/Web/lan-frontend/app/register/page.tsx
+++ b/src/Web/lan-frontend/app/register/page.tsx
@@ -461,9 +461,9 @@ export default function RegisterPage() {
                   ))}
                 </optgroup>
                 <optgroup label="Gymnasium">
-                {["11", "12", "13"].map((g) => (
+                {["10", "11", "12"].map((g) => (
                   <option key={`gym${g}`} value={g}>
-                    Gymnasiet {g}
+                    Gymnasiet år {Number(g) - 9}
                   </option>
                 ))}
                 </optgroup>