diff --git a/wxPython/docs/CHANGES.txt b/wxPython/docs/CHANGES.txt
index d81a090d65..d13758551e 100644
--- a/wxPython/docs/CHANGES.txt
+++ b/wxPython/docs/CHANGES.txt
@@ -9,7 +9,9 @@ sizers.  This means that the item's GetAdjustedBestSize will be called
 when calculating layout and the return value from that will be used
 for the minimum size.  Added wx.FIXED_MINSIZE flag for when you would
 like the old behavior but you should only need it when your desired
-size is smaller than the item's GetBestSize()
+size is smaller than the item's GetBestSize.  When a window is added
+to a sizer it's initial size, if any, is set as the window's minimal
+size using SetSizeHints if there isn't already a minimal size.
 
 
 2.5.1.5
diff --git a/wxPython/docs/MigrationGuide.txt b/wxPython/docs/MigrationGuide.txt
index 761ec50b11..bf4e356de2 100644
--- a/wxPython/docs/MigrationGuide.txt
+++ b/wxPython/docs/MigrationGuide.txt
@@ -456,7 +456,9 @@ GetAdjustedBestSize will be called when calculating layout and the
 return value from that will be used for the minimum size.  Added
 wx.FIXED_MINSIZE flag for when you would like the old behavior but you
 should only need it when your desired size is smaller than the item's
-GetBestSize().
+GetBestSize.  When a window is added to a sizer it's initial size, if
+any, is set as the window's minimal size using SetSizeHints if there
+isn't already a minimal size.
 
 
 PlatformInfo