diff --git a/robotoff/prediction/nutrition_extraction.py b/robotoff/prediction/nutrition_extraction.py
index d42c82c26e..2b157aa69f 100644
--- a/robotoff/prediction/nutrition_extraction.py
+++ b/robotoff/prediction/nutrition_extraction.py
@@ -535,7 +535,7 @@ def match_nutrient_value(
         prefix = prefix.strip()
         value = f"{prefix} {value}"
 
-    if value == "O":
+    if value in ("O", "o"):
         # The OCR engine failed to recognize correctly "0" (zero) and uses
         # "O" (letter O) instead
         value = "0"
diff --git a/tests/unit/prediction/test_nutrition_extraction.py b/tests/unit/prediction/test_nutrition_extraction.py
index 98e6e16fed..b072b0c4a4 100644
--- a/tests/unit/prediction/test_nutrition_extraction.py
+++ b/tests/unit/prediction/test_nutrition_extraction.py
@@ -392,6 +392,7 @@ def test_aggregate_entities_multiple_entities(self):
         # Missing unit and value ends with '9' but not in target entity list
         ("25.9", "iron_100g", ("25.9", None, True)),
         ("O g", "salt_100g", ("0", "g", True)),
+        ("o mg", "sodium_100g", ("0", "mg", True)),
         ("O", "salt_100g", ("0", None, True)),
         # Missing unit and value ends with '9' or '8'
         ("0.19", "saturated_fat_100g", ("0.1", "g", True)),