diff --git a/app/TermsOfUseVersion.php b/app/TermsOfUseVersion.php
index e4472407..25f9b027 100644
--- a/app/TermsOfUseVersion.php
+++ b/app/TermsOfUseVersion.php
@@ -13,6 +13,12 @@
 class TermsOfUseVersion extends Model {
     use HasFactory;
 
+    protected $primaryKey = 'version';
+
+    protected $keyType = 'string';
+
+    public $incrementing = false;
+
     protected $table = 'tou_versions';
 
     const FIELDS = [
@@ -24,11 +30,6 @@ class TermsOfUseVersion extends Model {
 
     protected $visible = self::FIELDS;
 
-    protected $casts = [
-        'version' => 'string',
-        'active' => 'boolean',
-    ];
-
     public static function latestActiveVersion(): ?self {
         return self::query()->where('active', true)->latest()->first();
     }
diff --git a/app/UserTermsOfUseAcceptance.php b/app/UserTermsOfUseAcceptance.php
index 3a13bcf9..5a6de0d4 100644
--- a/app/UserTermsOfUseAcceptance.php
+++ b/app/UserTermsOfUseAcceptance.php
@@ -20,7 +20,6 @@ class UserTermsOfUseAcceptance extends Model {
     protected $visible = self::FIELDS;
 
     protected $casts = [
-        'tou_version' => 'string',
         'tou_accepted_at' => 'datetime',
     ];
 
diff --git a/database/migrations/2026_01_08_144222_update_tou_versions_and_tou_acceptances_tables.php.php b/database/migrations/2026_01_08_144222_update_tou_versions_and_tou_acceptances_tables.php.php
new file mode 100644
index 00000000..80e32517
--- /dev/null
+++ b/database/migrations/2026_01_08_144222_update_tou_versions_and_tou_acceptances_tables.php.php
@@ -0,0 +1,34 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration {
+    /**
+     * Run the migrations.
+     */
+    public function up(): void {
+        Schema::table('tou_versions', function (Blueprint $table) {
+            $table->dropColumn('id');
+            $table->char('version', 10)->primary()->change();
+        });
+
+        Schema::table('tou_acceptances', function (Blueprint $table) {
+            $table->char('tou_version', 10)->change();
+            $table->foreign('tou_version')
+                ->references('version')
+                ->on('tou_versions')
+                ->cascadeOnUpdate()
+                ->restrictOnDelete();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void {
+        Schema::dropIfExists('tou_versions');
+        Schema::dropIfExists('tou_acceptances');
+    }
+};