diff --git a/app/Http/Controllers/Admin/Manage/CourseRegistrationController.php b/app/Http/Controllers/Admin/Manage/CourseRegistrationController.php
index a912333..89148a8 100644
--- a/app/Http/Controllers/Admin/Manage/CourseRegistrationController.php
+++ b/app/Http/Controllers/Admin/Manage/CourseRegistrationController.php
@@ -93,6 +93,7 @@ public function show(Student $student): Response
             'submissions' => $submissions,
             'semesters' => $semesters->values(),
             'openSemesters' => $activeTerm?->open_semesters ?? [],
+            'studentCurrentSemester' => $student->current_semester,
             'hasActiveTerm' => $activeTerm !== null,
             'backHref' => $backHref,
             'canReview' => $canReview,
@@ -114,6 +115,7 @@ public function save(Student $student, string $semester, SaveCourseRegistrationR
             $activeTerm->id,
             $semesterNumber,
             $activeTerm->open_semesters ?? [],
+            $student->current_semester,
         );
 
         $selectedIds = array_values(array_intersect(
diff --git a/app/Services/Admin/Manage/CourseRegistrationService.php b/app/Services/Admin/Manage/CourseRegistrationService.php
index c1a242a..77b3cac 100644
--- a/app/Services/Admin/Manage/CourseRegistrationService.php
+++ b/app/Services/Admin/Manage/CourseRegistrationService.php
@@ -159,9 +159,9 @@ public function availableCourseClasses(int $departmentId, int $academicTermId):
      * @param  array<int, int>  $openSemesters
      * @return array<int, int>
      */
-    public function selectableCourseClassIds(int $departmentId, int $academicTermId, ?int $semesterNumber, array $openSemesters): array
+    public function selectableCourseClassIds(int $departmentId, int $academicTermId, ?int $semesterNumber, array $openSemesters, ?int $studentCurrentSemester): array
     {
-        if ($semesterNumber === null || ! in_array($semesterNumber, $openSemesters, true)) {
+        if ($semesterNumber === null || $semesterNumber !== $studentCurrentSemester || ! in_array($semesterNumber, $openSemesters, true)) {
             return [];
         }
 
diff --git a/resources/js/pages/admin/manage/course-registrations/show.tsx b/resources/js/pages/admin/manage/course-registrations/show.tsx
index 8e037db..851adb8 100644
--- a/resources/js/pages/admin/manage/course-registrations/show.tsx
+++ b/resources/js/pages/admin/manage/course-registrations/show.tsx
@@ -48,6 +48,18 @@ const RegistrationStatusVariants: Record<
     rejected: 'destructive',
 };
 
+function isSemesterOpenForStudent(
+    semester: number | null,
+    openSemesters: number[],
+    studentCurrentSemester: number,
+): boolean {
+    return (
+        semester !== null &&
+        semester === studentCurrentSemester &&
+        openSemesters.includes(semester)
+    );
+}
+
 function InfoRow({ label, value }: { label: string; value: React.ReactNode }) {
     return (
         <div className="grid grid-cols-[auto_1fr] gap-x-2 text-sm">
@@ -516,7 +528,11 @@ function SemesterCard({
                                             }
                                             alt="Tanda tangan mahasiswa"
                                             error={errors.signature}
-                                            editable={!isViewOnly && !isLocked}
+                                            editable={
+                                                isSemesterOpen &&
+                                                !isViewOnly &&
+                                                !isLocked
+                                            }
                                         />
                                         <p className="font-semibold">
                                             {student?.user?.profile
@@ -608,6 +624,7 @@ type Props = {
     submissions: Record<string, CourseRegistrationSubmission>;
     semesters: (number | null)[];
     openSemesters: number[];
+    studentCurrentSemester: number;
     hasActiveTerm: boolean;
     backHref: string | null;
     canReview: boolean;
@@ -619,6 +636,7 @@ export default function CourseRegistrationDetail({
     submissions,
     semesters,
     openSemesters,
+    studentCurrentSemester,
     hasActiveTerm,
     backHref,
     canReview,
@@ -670,8 +688,11 @@ export default function CourseRegistrationDetail({
                                     {semester !== null
                                         ? `Semester ${semester}`
                                         : 'Lainnya'}
-                                    {!openSemesters.includes(semester ?? -1) &&
-                                        ' (Ditutup)'}
+                                    {!isSemesterOpenForStudent(
+                                        semester,
+                                        openSemesters,
+                                        studentCurrentSemester,
+                                    ) && ' (Ditutup)'}
                                 </TabsTrigger>
                             ))}
                         </TabsList>
@@ -684,8 +705,10 @@ export default function CourseRegistrationDetail({
                         semester={currentSemester}
                         submission={currentSubmission}
                         studentId={studentId}
-                        isSemesterOpen={openSemesters.includes(
-                            currentSemester ?? -1,
+                        isSemesterOpen={isSemesterOpenForStudent(
+                            currentSemester,
+                            openSemesters,
+                            studentCurrentSemester,
                         )}
                         backHref={backHref}
                         canReview={canReview}