diff --git a/src/xrc/xh_auinotbk.cpp b/src/xrc/xh_auinotbk.cpp
index 2035787291..df7498394f 100644
--- a/src/xrc/xh_auinotbk.cpp
+++ b/src/xrc/xh_auinotbk.cpp
@@ -22,7 +22,8 @@
 wxIMPLEMENT_DYNAMIC_CLASS(wxAuiNotebookXmlHandler, wxXmlResourceHandler);
 
 wxAuiNotebookXmlHandler::wxAuiNotebookXmlHandler()
-    : wxXmlResourceHandler()
+    : wxXmlResourceHandler(),
+      m_isInside(false)
 {
     XRC_ADD_STYLE(wxAUI_NB_DEFAULT_STYLE);
     XRC_ADD_STYLE(wxAUI_NB_TAB_SPLIT);