diff --git a/django/contrib/postgres/forms/hstore.py b/django/contrib/postgres/forms/hstore.py
index 6a20f7b729..f824f78c3e 100644
--- a/django/contrib/postgres/forms/hstore.py
+++ b/django/contrib/postgres/forms/hstore.py
@@ -20,7 +20,7 @@ class HStoreField(forms.CharField):
 
     def prepare_value(self, value):
         if isinstance(value, dict):
-            return json.dumps(value)
+            return json.dumps(value, ensure_ascii=False)
         return value
 
     def to_python(self, value):
diff --git a/tests/postgres_tests/test_hstore.py b/tests/postgres_tests/test_hstore.py
index 2aaad637c6..cac3eb742a 100644
--- a/tests/postgres_tests/test_hstore.py
+++ b/tests/postgres_tests/test_hstore.py
@@ -410,6 +410,13 @@ class TestFormField(PostgreSQLSimpleTestCase):
         form_w_hstore = HStoreFormTest({"f1": '{"a": 2}'}, initial={"f1": {"a": 1}})
         self.assertTrue(form_w_hstore.has_changed())
 
+    def test_prepare_value(self):
+        field = forms.HStoreField()
+        self.assertEqual(
+            field.prepare_value({"aira_maplayer": "Αρδευτικό δίκτυο"}),
+            '{"aira_maplayer": "Αρδευτικό δίκτυο"}',
+        )
+
 
 class TestValidator(PostgreSQLSimpleTestCase):
     def test_simple_valid(self):