diff --git a/app/Http/Requests/Admin/Manage/CourseClassRequest.php b/app/Http/Requests/Admin/Manage/CourseClassRequest.php
index a67692d..3c56804 100644
--- a/app/Http/Requests/Admin/Manage/CourseClassRequest.php
+++ b/app/Http/Requests/Admin/Manage/CourseClassRequest.php
@@ -3,6 +3,8 @@
 namespace App\Http\Requests\Admin\Manage;
 
 use App\Enums\ClassMethod;
+use App\Enums\Semester;
+use App\Models\AcademicTerm;
 use App\Models\Course;
 use App\Models\Lecturer;
 use Illuminate\Foundation\Http\FormRequest;
@@ -18,6 +20,26 @@ public function authorize(): bool
     public function rules(): array
     {
         $academicTermId = $this->input('academic_term_id');
+        $academicTerm = $academicTermId ? AcademicTerm::find($academicTermId) : null;
+
+        $semesterParityRule = function ($attribute, $value, $fail) use ($academicTerm) {
+            if (! $academicTerm) {
+                return;
+            }
+
+            $semesterNumber = Course::find($value)?->semester_number;
+
+            if ($semesterNumber === null) {
+                return;
+            }
+
+            $isOddSemester = $semesterNumber % 2 === 1;
+            $matches = $academicTerm->semester === Semester::odd ? $isOddSemester : ! $isOddSemester;
+
+            if (! $matches) {
+                $fail('Mata kuliah semester '.$semesterNumber.' tidak sesuai dengan periode '.$academicTerm->semester->label().'.');
+            }
+        };
 
         if ($this->isMethod('post')) {
             return [
@@ -28,6 +50,7 @@ public function rules(): array
                     Rule::unique('course_classes', 'course_id')
                         ->where('academic_term_id', $academicTermId)
                         ->whereNull('deleted_at'),
+                    $semesterParityRule,
                 ],
                 'lecturer_id' => [
                     'required',
@@ -61,6 +84,7 @@ function ($attribute, $value, $fail) {
                     ->where('academic_term_id', $academicTermId)
                     ->whereNull('deleted_at')
                     ->ignore($this->route('course_class')?->id),
+                $semesterParityRule,
             ],
             'lecturer_id' => [
                 'required',
diff --git a/app/Http/Requests/Admin/Manage/DuplicateCourseClassesRequest.php b/app/Http/Requests/Admin/Manage/DuplicateCourseClassesRequest.php
index e2ea5d9..6ed68e9 100644
--- a/app/Http/Requests/Admin/Manage/DuplicateCourseClassesRequest.php
+++ b/app/Http/Requests/Admin/Manage/DuplicateCourseClassesRequest.php
@@ -2,6 +2,7 @@
 
 namespace App\Http\Requests\Admin\Manage;
 
+use App\Models\AcademicTerm;
 use Illuminate\Foundation\Http\FormRequest;
 use Illuminate\Validation\Rule;
 use Illuminate\Validation\Validator;
@@ -26,6 +27,15 @@ public function withValidator(Validator $validator): void
         $validator->after(function (Validator $validator) {
             if ($this->input('source_academic_term_id') === $this->input('target_academic_term_id')) {
                 $validator->errors()->add('target_academic_term_id', 'Periode tujuan harus berbeda dari periode sumber.');
+
+                return;
+            }
+
+            $sourceTerm = AcademicTerm::find($this->input('source_academic_term_id'));
+            $targetTerm = AcademicTerm::find($this->input('target_academic_term_id'));
+
+            if ($sourceTerm && $targetTerm && $sourceTerm->semester !== $targetTerm->semester) {
+                $validator->errors()->add('target_academic_term_id', 'Periode tujuan harus semester yang sama dengan periode sumber (Ganjil ke Ganjil, Genap ke Genap).');
             }
         });
     }
diff --git a/resources/js/pages/admin/manage/course-classes/index.tsx b/resources/js/pages/admin/manage/course-classes/index.tsx
index 929d0c3..99c3786 100644
--- a/resources/js/pages/admin/manage/course-classes/index.tsx
+++ b/resources/js/pages/admin/manage/course-classes/index.tsx
@@ -810,6 +810,15 @@ function DuplicateForm({
     const [sourceTermId, setSourceTermId] = useState('');
     const [targetTermId, setTargetTermId] = useState('');
 
+    const sourceTerm = academicTerms.find(
+        (term) => String(term.id) === sourceTermId,
+    );
+    const targetOptions = academicTerms.filter(
+        (term) =>
+            String(term.id) !== sourceTermId &&
+            (!sourceTerm || term.semester === sourceTerm.semester),
+    );
+
     function reset() {
         setSourceTermId('');
         setTargetTermId('');
@@ -834,8 +843,10 @@ function DuplicateForm({
                     <p className="text-sm text-muted-foreground">
                         Menyalin semua kelas mata kuliah (mata kuliah, dosen
                         pengampu, metode) dari periode sumber ke periode
-                        tujuan. Mata kuliah yang sudah punya kelas di periode
-                        tujuan akan dilewati.
+                        tujuan. Periode tujuan hanya bisa dipilih dari
+                        semester yang sama (Ganjil ke Ganjil, Genap ke Genap).
+                        Mata kuliah yang sudah punya kelas di periode tujuan
+                        akan dilewati.
                     </p>
                     <div className="grid gap-2">
                         <Label>
@@ -849,7 +860,10 @@ function DuplicateForm({
                         />
                         <Select
                             value={sourceTermId}
-                            onValueChange={setSourceTermId}
+                            onValueChange={(value) => {
+                                setSourceTermId(value);
+                                setTargetTermId('');
+                            }}
                         >
                             <SelectTrigger className="w-full">
                                 <SelectValue placeholder="Pilih periode sumber" />
@@ -882,12 +896,19 @@ function DuplicateForm({
                         <Select
                             value={targetTermId}
                             onValueChange={setTargetTermId}
+                            disabled={!sourceTermId}
                         >
                             <SelectTrigger className="w-full">
-                                <SelectValue placeholder="Pilih periode tujuan" />
+                                <SelectValue
+                                    placeholder={
+                                        sourceTermId
+                                            ? 'Pilih periode tujuan'
+                                            : 'Pilih periode sumber terlebih dahulu'
+                                    }
+                                />
                             </SelectTrigger>
                             <SelectContent>
-                                {academicTerms.map((term) => (
+                                {targetOptions.map((term) => (
                                     <SelectItem
                                         key={term.id}
                                         value={String(term.id)}