diff --git a/whatsnew.htm b/whatsnew.htm
index caae8666..e5144d1a 100644
--- a/whatsnew.htm
+++ b/whatsnew.htm
@@ -32,6 +32,7 @@
 <p><a name="6.4.1"></a><span class="ver">6.4.1-dev </span><span class="date">(?)</span></p>
 
 <ul>
+  <li>Compiler IDE: Added mouseover tooltips for all Pascal Scripting support functions and class members showing their prototype. Always shows all classes' members instead of just those of the current object's class.</li>
   <li><i>Fix:</i> In 6.4.0, a custom form shown using <tt>[Code]</tt> didn't have a taskbar button if Setup's wizard was not visible at the time.</li>
 </ul>