diff --git a/poincare/include/poincare/unit.h b/poincare/include/poincare/unit.h
index ed1e8e0f8..81e93e64c 100644
--- a/poincare/include/poincare/unit.h
+++ b/poincare/include/poincare/unit.h
@@ -235,7 +235,7 @@ public:
         Representative("week", "7*24*60*60*_s",
             Representative::Prefixable::No,
             NoPrefix),
-        Representative("month", "30*7*24*60*60*_s",
+        Representative("month", "30*24*60*60*_s",
             Representative::Prefixable::No,
             NoPrefix),
         Representative("year", "365.25*24*60*60*_s",