diff --git a/open_prices/prices/tests.py b/open_prices/prices/tests.py
index 529cf8e8..eb5b2530 100644
--- a/open_prices/prices/tests.py
+++ b/open_prices/prices/tests.py
@@ -119,6 +119,12 @@ def test_price_without_product_validation(self):
             cm.exception.messages[0],
             "Invalid value: 'test', expected value to be in 'lang:tag' format",
         )
+        PriceFactory(
+            product_code=None,
+            category_tag="fr: Grenoble",  # valid (even if not in the taxonomy)
+            price=3,
+            price_per=price_constants.PRICE_PER_KILOGRAM,
+        )
         PriceFactory(
             product_code=None,
             category_tag="en:tomatoes",
@@ -131,7 +137,7 @@ def test_price_without_product_validation(self):
             PriceFactory,
             product_code=None,
             category_tag="en:tomatoes",
-            labels_tags="en:organic",
+            labels_tags="en:organic",  # should be a list
             price=3,
             price_per=price_constants.PRICE_PER_KILOGRAM,
         )
@@ -140,7 +146,7 @@ def test_price_without_product_validation(self):
             PriceFactory,
             product_code=None,
             category_tag="en:tomatoes",
-            labels_tags=["en:organic", "test"],
+            labels_tags=["en:organic", "test"],  # not valid
             price=3,
             price_per=price_constants.PRICE_PER_KILOGRAM,
         )
@@ -158,7 +164,7 @@ def test_price_without_product_validation(self):
             product_code=None,
             category_tag="en:tomatoes",
             labels_tags=["en:organic"],
-            origins_tags="en:france",
+            origins_tags="en:france",  # should be a list
             price=3,
             price_per=price_constants.PRICE_PER_KILOGRAM,
         )
@@ -168,7 +174,7 @@ def test_price_without_product_validation(self):
             product_code=None,
             category_tag="en:tomatoes",
             labels_tags=["en:organic"],
-            origins_tags=["en:france", "test"],
+            origins_tags=["en:france", "test"],  # not valid
             price=3,
             price_per=price_constants.PRICE_PER_KILOGRAM,
         )