diff --git a/PowerEditor/src/WinControls/ProjectPanel/ProjectPanel.cpp b/PowerEditor/src/WinControls/ProjectPanel/ProjectPanel.cpp
index f10304c86..585d7f005 100644
--- a/PowerEditor/src/WinControls/ProjectPanel/ProjectPanel.cpp
+++ b/PowerEditor/src/WinControls/ProjectPanel/ProjectPanel.cpp
@@ -917,7 +917,7 @@ void ProjectPanel::popupMenuCmd(int cmdID)
 			}
 
 			FileDialog fDlg(_hSelf, ::GetModuleHandle(NULL));
-			fDlg.setExtFilter(TEXT("All types"), TEXT(".*"), NULL);
+			setFileExtFilter(fDlg);
 			if (TCHAR *fn = fDlg.doOpenSingleFileDlg())
 			{
 				if (!openWorkSpace(fn))
@@ -1043,7 +1043,8 @@ void ProjectPanel::popupMenuCmd(int cmdID)
 bool ProjectPanel::saveWorkSpaceAs(bool saveCopyAs)
 {
 	FileDialog fDlg(_hSelf, ::GetModuleHandle(NULL));
-	fDlg.setExtFilter(TEXT("All types"), TEXT(".*"), NULL);
+	setFileExtFilter(fDlg);
+	fDlg.setExtIndex(0);		// 0 index for "custom extention" type if any else for "All types *.*"
 
 	if (TCHAR *fn = fDlg.doSaveDlg())
 	{
@@ -1058,6 +1059,20 @@ bool ProjectPanel::saveWorkSpaceAs(bool saveCopyAs)
 	return false;
 }
 
+void ProjectPanel::setFileExtFilter(FileDialog & fDlg)
+{
+	const TCHAR *ext = NppParameters::getInstance()->getNppGUI()._definedWorkspaceExt.c_str();
+	generic_string workspaceExt = TEXT("");
+	if (*ext != '\0')
+	{
+		if (*ext != '.')
+			workspaceExt += TEXT(".");
+		workspaceExt += ext;
+		fDlg.setExtFilter(TEXT("Workspace file"), workspaceExt.c_str(), NULL);
+	}
+	fDlg.setExtFilter(TEXT("All types"), TEXT(".*"), NULL);
+}
+
 void ProjectPanel::addFiles(HTREEITEM hTreeItem)
 {
 	FileDialog fDlg(_hSelf, ::GetModuleHandle(NULL));
diff --git a/PowerEditor/src/WinControls/ProjectPanel/ProjectPanel.h b/PowerEditor/src/WinControls/ProjectPanel/ProjectPanel.h
index c22cb8b61..aa1763a27 100644
--- a/PowerEditor/src/WinControls/ProjectPanel/ProjectPanel.h
+++ b/PowerEditor/src/WinControls/ProjectPanel/ProjectPanel.h
@@ -26,14 +26,9 @@
 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
 
-#ifndef PROJECTPANEL_H
-#define  PROJECTPANEL_H
+#pragma once
 
-//#include <windows.h>
-#ifndef DOCKINGDLGINTERFACE_H
 #include "DockingDlgInterface.h"
-#endif //DOCKINGDLGINTERFACE_H
-
 #include "TreeView.h"
 #include "ProjectPanel_rc.h"
 
@@ -68,6 +63,7 @@ enum NodeType {
 };
 
 class TiXmlNode;
+class FileDialog;
 
 class ProjectPanel : public DockingDlgInterface {
 public:
@@ -141,6 +137,7 @@ protected:
 	void showContextMenu(int x, int y);
 	generic_string getAbsoluteFilePath(const TCHAR * relativePath);
 	void openSelectFile();
+	void setFileExtFilter(FileDialog & fDlg);
 };
 
 class FileRelocalizerDlg : public StaticDialog
@@ -167,5 +164,3 @@ private :
 	generic_string _fullFilePath;
 
 };
-
-#endif // PROJECTPANEL_H