diff --git a/apps/registration/migrations/0003_alter_participantregistration_zip_code.py b/apps/registration/migrations/0003_alter_participantregistration_zip_code.py
new file mode 100644
index 0000000..9846197
--- /dev/null
+++ b/apps/registration/migrations/0003_alter_participantregistration_zip_code.py
@@ -0,0 +1,19 @@
+# Generated by Django 3.2.13 on 2023-01-16 22:13
+
+import django.core.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('registration', '0002_auto_20230110_2031'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='participantregistration',
+            name='zip_code',
+            field=models.PositiveIntegerField(validators=[django.core.validators.MinValueValidator(1000), django.core.validators.MaxValueValidator(99999)], verbose_name='zip code'),
+        ),
+    ]
diff --git a/apps/registration/models.py b/apps/registration/models.py
index a3f1d4c..8bd9fb4 100644
--- a/apps/registration/models.py
+++ b/apps/registration/models.py
@@ -139,7 +139,7 @@ class ParticipantRegistration(Registration):
         verbose_name=_("address"),
     )
 
-    zip_code = models.PositiveSmallIntegerField(
+    zip_code = models.PositiveIntegerField(
         verbose_name=_("zip code"),
         validators=[MinValueValidator(1000), MaxValueValidator(99999)],
     )