diff --git a/include/wx/os2/notebook.h b/include/wx/os2/notebook.h
index 4adaa2c64f..48e60c5b08 100644
--- a/include/wx/os2/notebook.h
+++ b/include/wx/os2/notebook.h
@@ -57,7 +57,7 @@ public:
     // ---------
     // Get number of pages in the dialog
     //
-           int      GetPageCount(void) const;
+    size_t GetPageCount(void) const;
 
     //
     // Set the currently selected page, return the index of the previously
diff --git a/src/os2/notebook.cpp b/src/os2/notebook.cpp
index fe64de1281..af5ac8b27e 100644
--- a/src/os2/notebook.cpp
+++ b/src/os2/notebook.cpp
@@ -186,7 +186,7 @@ WXDWORD wxNotebook::OS2GetStyle (
 // wxNotebook accessors
 // ----------------------------------------------------------------------------
 
-int wxNotebook::GetPageCount() const
+size_t wxNotebook::GetPageCount() const
 {
     int                             nPageInternal = m_pages.Count();
     int                             nPageAPI = (int)::WinSendMsg(GetHWND(), BKM_QUERYPAGECOUNT, (MPARAM)0, (MPARAM)BKA_END);