diff --git a/UPGRADE_TO_2_3 b/UPGRADE_TO_2_3
index 7f860be93..c0b451f22 100644
--- a/UPGRADE_TO_2_3
+++ b/UPGRADE_TO_2_3
@@ -7,3 +7,21 @@ and strip a trailing "s" character if there is one.
 # Merge copies non persisted properties too
 
 When merging an entity in UoW not only mapped properties are copied, but also others.
+
+# Query, QueryBuilder and NativeQuery parameters *BC break*
+
+From now on, parameters in queries is an ArrayCollection instead of a simple array.
+This affects heavily the usage of setParameters(), because it will not append anymore
+parameters to query, but will actually override the already defined ones.
+Whenever you are retrieving a parameter (ie. $query->getParameter(1)), you will
+receive an instance of Query\Parameter, which contains the methods "getName",
+"getValue" and "getType". Parameters are also only converted to when necessary, and
+not when they are set.
+
+Also, related functions were affected:
+
+* execute(ArrayCollection $parameters, $hydrationMode)
+* iterate(ArrayCollection $parameters, $hydrationMode)
+* setParameters(ArrayCollection $parameters)
+* getParameters()
+* getParameter($key)
\ No newline at end of file