diff --git a/lib/ProductOpener/DataQualityFood.pm b/lib/ProductOpener/DataQualityFood.pm
index de185d5915bb2..8ac808984760b 100644
--- a/lib/ProductOpener/DataQualityFood.pm
+++ b/lib/ProductOpener/DataQualityFood.pm
@@ -1203,12 +1203,18 @@ Checks related to the quantity and serving quantity.
 
 =cut
 
+# Check quantity values. See https://en.wiki.openfoodfacts.org/Products_quantities
 sub check_quantity ($product_ref) {
 
 	# quantity contains "e" - might be an indicator that the user might have wanted to use "℮" \N{U+212E}
-	if (    (defined $product_ref->{quantity})
-		and ($product_ref->{quantity} =~ /(?:.*e$)|(?:[0-9]+\s*[kmc]?[gl]?\s*e)/i)
-		and (not($product_ref->{quantity} =~ /\N{U+212E}/i)))
+	# example: 650 g e
+	if (
+		(defined $product_ref->{quantity})
+		# contains "kg e", or "g e", or "cl e", etc.
+		and ($product_ref->{quantity} =~ /(?:[0-9]+\s*[kmc]?[gl]\s*e)/i)
+		# contains the "℮" symbol
+		and (not($product_ref->{quantity} =~ /\N{U+212E}/i))
+		)
 	{
 		push @{$product_ref->{data_quality_info_tags}}, "en:quantity-contains-e";
 	}
diff --git a/tests/unit/dataqualityfood.t b/tests/unit/dataqualityfood.t
index 9d336d52485d2..a269c5df9aca9 100644
--- a/tests/unit/dataqualityfood.t
+++ b/tests/unit/dataqualityfood.t
@@ -6,6 +6,7 @@ use utf8;
 use Test::More;
 
 use ProductOpener::DataQuality qw/:all/;
+use ProductOpener::DataQualityFood qw/:all/;
 use ProductOpener::Tags qw/:all/;
 use ProductOpener::Ingredients qw/:all/;
 
@@ -707,4 +708,40 @@ check_quality_and_test_product_has_quality_tag(
 	'sum of fructose plus glucose plus maltose plus lactose plus sucrose cannot be greater than sugars', 0
 );
 
+# testing of ProductOpener::DataQualityFood::check_quantity subroutine
+$product_ref = {quantity => "300g"};
+ProductOpener::DataQuality::check_quality($product_ref);
+check_quality_and_test_product_has_quality_tag($product_ref, 'en:quantity-contains-e',
+	'quantity does not contain e', 0);
+$product_ref = {quantity => "1 verre"};
+ProductOpener::DataQuality::check_quality($product_ref);
+check_quality_and_test_product_has_quality_tag($product_ref, 'en:quantity-contains-e',
+	'quantity does not contain e', 0);
+$product_ref = {quantity => "1 litre"};
+ProductOpener::DataQuality::check_quality($product_ref);
+check_quality_and_test_product_has_quality_tag($product_ref, 'en:quantity-contains-e',
+	'quantity does not contain e', 0);
+$product_ref = {quantity => "225 g ℮"};
+ProductOpener::DataQuality::check_quality($product_ref);
+check_quality_and_test_product_has_quality_tag($product_ref, 'en:quantity-contains-e', 'quantity does not contain e',
+	0);
+$product_ref = {quantity => "300ge"};
+ProductOpener::DataQuality::check_quality($product_ref);
+check_quality_and_test_product_has_quality_tag($product_ref, 'en:quantity-contains-e', 'quantity contains e', 1);
+$product_ref = {quantity => "300mge"};
+ProductOpener::DataQuality::check_quality($product_ref);
+check_quality_and_test_product_has_quality_tag($product_ref, 'en:quantity-contains-e', 'quantity contains e', 1);
+$product_ref = {quantity => "300 mg e"};
+ProductOpener::DataQuality::check_quality($product_ref);
+check_quality_and_test_product_has_quality_tag($product_ref, 'en:quantity-contains-e', 'quantity contains e', 1);
+$product_ref = {quantity => "200 g e (2x100g)"};
+ProductOpener::DataQuality::check_quality($product_ref);
+check_quality_and_test_product_has_quality_tag($product_ref, 'en:quantity-contains-e', 'quantity contains e', 1);
+$product_ref = {quantity => "1kge35.27oz"};
+ProductOpener::DataQuality::check_quality($product_ref);
+check_quality_and_test_product_has_quality_tag($product_ref, 'en:quantity-contains-e', 'quantity contains e', 1);
+$product_ref = {quantity => "300 ml e / 342 g"};
+ProductOpener::DataQuality::check_quality($product_ref);
+check_quality_and_test_product_has_quality_tag($product_ref, 'en:quantity-contains-e', 'quantity contains e', 1);
+
 done_testing();