diff --git a/storage_thumbnail/models/thumbnail_mixin.py b/storage_thumbnail/models/thumbnail_mixin.py
index 2db06aff65..736eb09647 100644
--- a/storage_thumbnail/models/thumbnail_mixin.py
+++ b/storage_thumbnail/models/thumbnail_mixin.py
@@ -101,6 +101,7 @@ def get_existing_thumbnail(self, size_x, size_y, url_key=None):
         return thumbnail
 
     def get_or_create_thumbnail(self, size_x, size_y, url_key=None):
+        url_key = self._get_url_key(url_key)
         thumbnail = self.get_existing_thumbnail(size_x, size_y, url_key=url_key)
         if not thumbnail and self.data:
             vals = self.env["storage.thumbnail"]._prepare_thumbnail(
diff --git a/storage_thumbnail/tests/test_thumbnail.py b/storage_thumbnail/tests/test_thumbnail.py
index 44bacbb7ba..9db0b0522d 100644
--- a/storage_thumbnail/tests/test_thumbnail.py
+++ b/storage_thumbnail/tests/test_thumbnail.py
@@ -51,6 +51,18 @@ def test_thumbnail(self):
         thumb.unlink()
         self.assertTrue(file_id.to_delete)
 
+    def test_image_get_or_create_thumbnail_no_duplicate(self):
+        # Ensure no duplicate is generated thanks to unique url_key
+        image = self._create_image()
+        self.assertTrue(image.url)
+        self.assertEqual(len(image.thumbnail_ids), 2)
+        thumb = image.thumb_small_id
+        thumb.url_key = "test"
+        existing_thumb = image.get_or_create_thumbnail(
+            thumb.size_x, thumb.size_y, url_key="TEST"
+        )
+        self.assertEqual(thumb, existing_thumb)
+
     def test_model(self):
         image = self._create_image()
         self.assertTrue(image.url)