diff --git a/samples/splitter/splitter.cpp b/samples/splitter/splitter.cpp
index cd05d8ab88..0ed8ae07f2 100644
--- a/samples/splitter/splitter.cpp
+++ b/samples/splitter/splitter.cpp
@@ -257,6 +257,12 @@ MyFrame::MyFrame()
     menuBar->Check(SPLIT_LIVE, true);
     m_splitter = new MySplitterWindow(this);
 
+    // If you use non-zero gravity you must initialize the splitter with its
+    // correct initial size, otherwise it will change the sash position by a
+    // huge amount when it's resized from its initial default size to its real
+    // size when the frame lays it out. This wouldn't be necessary if default
+    // zero gravity were used (although it would do no harm neither).
+    m_splitter->SetSize(GetClientSize());
     m_splitter->SetSashGravity(1.0);
 
 #if 1
diff --git a/src/generic/splitter.cpp b/src/generic/splitter.cpp
index 5b0bd620a8..8c03ba8ebd 100644
--- a/src/generic/splitter.cpp
+++ b/src/generic/splitter.cpp
@@ -435,6 +435,8 @@ void wxSplitterWindow::OnSize(wxSizeEvent& event)
         return;
     }
 
+    const wxSize curSize = event.GetSize();
+
     // Update the sash position if needed.
     //
     // Notice that we shouldn't do this if the sash position requested by user
@@ -442,10 +444,7 @@ void wxSplitterWindow::OnSize(wxSizeEvent& event)
     // modified it before this happens.
     if ( m_windowTwo && m_requestedSashPosition == INT_MAX )
     {
-        int w, h;
-        GetClientSize(&w, &h);
-
-        int size = m_splitMode == wxSPLIT_VERTICAL ? w : h;
+        int size = m_splitMode == wxSPLIT_VERTICAL ? curSize.x : curSize.y;
 
         int old_size = m_splitMode == wxSPLIT_VERTICAL ? m_lastSize.x : m_lastSize.y;
 
@@ -468,6 +467,8 @@ void wxSplitterWindow::OnSize(wxSizeEvent& event)
         }
     }
 
+    m_lastSize = curSize;
+
     SizeWindows();
 }