diff --git a/CHANGELOG b/CHANGELOG
index d030cc22f2..03b20515e4 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,4 @@
+* Do not apply promotion on free or empty product
 * Remove support for Python 2.7
 
 Version 4.8.0 - 2018-04-23
diff --git a/sale.py b/sale.py
index eded8daea4..a5b542cd1a 100644
--- a/sale.py
+++ b/sale.py
@@ -232,7 +232,7 @@ class SalePromotion(
                     yield category
                     category = category.parent
 
-        if line.quantity < 0:
+        if line.quantity <= 0 or line.unit_price <= 0:
             return False
         elif self.unit and line.unit.category != self.unit.category:
             return False