diff --git a/PowerEditor/src/NppIO.cpp b/PowerEditor/src/NppIO.cpp
index b23b96b47..ab815a751 100644
--- a/PowerEditor/src/NppIO.cpp
+++ b/PowerEditor/src/NppIO.cpp
@@ -1881,6 +1881,7 @@ const TCHAR * Notepad_plus::fileSaveSession(size_t nbFile, TCHAR ** fileNames)
 			sessionExt += TEXT(".");
 		sessionExt += ext;
 		fDlg.setExtFilter(TEXT("Session file"), sessionExt.c_str(), NULL);
+		fDlg.setExtIndex(0);		// 0 index for "custom extention types"
 	}
 	fDlg.setExtFilter(TEXT("All types"), TEXT(".*"), NULL);
 	sessionFileName = fDlg.doSaveDlg();