diff --git a/CHANGES.rst b/CHANGES.rst
index f8110a59..104fa939 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -91,6 +91,7 @@ Changes in this release include the following:
 
 * Fix for unexpected assertion inside wx.aui.AuiMDIChildFrame.Close.
 
+* Fix a bug in setting AuiDockingGuide size. (#727)
 
 
 
diff --git a/wx/lib/agw/aui/framemanager.py b/wx/lib/agw/aui/framemanager.py
index a8461ee0..456a01a0 100644
--- a/wx/lib/agw/aui/framemanager.py
+++ b/wx/lib/agw/aui/framemanager.py
@@ -2263,9 +2263,9 @@ class AuiSingleDockingGuide(AuiDockingGuide):
             else:
                 self.SetGuideShape()
 
-            self.SetSize(self.region.GetBox().GetSize())
+            self.SetClientSize(self.region.GetBox().GetSize())
         else:
-            self.SetSize((sizeX, sizeY))
+            self.SetClientSize((sizeX, sizeY))
 
         self.rect = wx.Rect(0, 0, sizeX, sizeY)
 
@@ -2414,7 +2414,7 @@ class AuiCenterDockingGuide(AuiDockingGuide):
         else:
             self.SetGuideShape()
 
-        self.SetSize(self.region.GetBox().GetSize())
+        self.SetClientSize(self.region.GetBox().GetSize())
 
         self.Bind(wx.EVT_ERASE_BACKGROUND, self.OnEraseBackground)
         self.Bind(wx.EVT_PAINT, self.OnPaint)