diff --git a/UPGRADE-4.0.md b/UPGRADE-4.0.md
index 77959fa48bab1..4132d06ab6146 100644
--- a/UPGRADE-4.0.md
+++ b/UPGRADE-4.0.md
@@ -226,6 +226,10 @@ Finder
 Form
 ----
 
+* The values of the `FormEvents::*` constants have been updated to match the
+  constant names. You should only update your application if you relied on the
+  constant values instead of their names.
+
  * The `choices_as_values` option of the `ChoiceType` has been removed.
 
  * Support for data objects that implements both `Traversable` and
@@ -326,6 +330,8 @@ Form
    }
    ```
 
+ * `FormRendererInterface::setTheme` and `FormRendererEngineInterface::setTheme` have a new optional argument `$useDefaultThemes` with a default value set to `true`.
+
 FrameworkBundle
 ---------------
 
@@ -662,7 +668,7 @@ Process
 
  * Extending `Process::run()`, `Process::mustRun()` and `Process::restart()` is
    not supported anymore.
-
+   
  * The `getEnhanceWindowsCompatibility()` and `setEnhanceWindowsCompatibility()` methods of the `Process` class have been removed.
 
 Profiler