diff --git a/gui/gui_about.cpp b/gui/gui_about.cpp
index bcbee0b..49ebfbb 100644
--- a/gui/gui_about.cpp
+++ b/gui/gui_about.cpp
@@ -69,6 +69,12 @@
 	mUpdateButton->Enable(false);
 	main_sizer->Add(mUpdateButton, 0, wxALL | wxEXPAND, 5);
 
+#ifdef DEBUG
+	main_sizer->AddSpacer(20);
+	mUpdateFromFileButton = new wxButton(this, ID_BUTTON_UPDATE_FROM_FILE, wxT("Update From File"), wxDefaultPosition, wxSize(120, 40));
+	main_sizer->Add(mUpdateFromFileButton, 0, wxALL | wxEXPAND, 5);
+#endif
+
 	main_sizer->SetSizeHints(this);
 	Centre();
 
@@ -174,12 +180,89 @@
 		wxT("Confirmation"), wxOK | wxCANCEL | wxICON_QUESTION | wxSTAY_ON_TOP | wxCENTRE);
 
 	if (msg.ShowModal() == wxID_OK)
-	{
 		UpdateFirmware();
-	}
 }
 
 
+#ifdef DEBUG
+
+void GuiAbout::OnButtonUpdateFromFileClicked(wxCommandEvent &event)
+{
+	wxFileDialog dialog(this, wxT("Open DFU file"), "", "", "DFU files (*.bin|*.bin", wxFD_OPEN | wxFD_FILE_MUST_EXIST);
+    if (dialog.ShowModal() == wxID_CANCEL)
+        return;
+
+	FILE* f = fopen(dialog.GetPath().mb_str(), "rb");
+	if (f == nullptr)
+	{
+		wxMessageDialog msg(this, wxT("Cannot open DFU file."), wxT("Error"), wxOK | wxSTAY_ON_TOP | wxCENTRE | wxICON_ERROR);
+		msg.ShowModal();
+		return;
+	}
+
+	if (fseek(f, 0, SEEK_END) != 0)
+	{
+		fclose(f);
+		wxMessageDialog msg(this, wxT("Cannot open DFU file."), wxT("Error"), wxOK | wxSTAY_ON_TOP | wxCENTRE | wxICON_ERROR);
+		msg.ShowModal();
+		return;
+	}
+
+	ssize_t fsize = ftell(f);
+	if (fsize < 0)
+	{
+		fclose(f);
+		wxMessageDialog msg(this, wxT("Cannot open DFU file."), wxT("Error"), wxOK | wxSTAY_ON_TOP | wxCENTRE | wxICON_ERROR);
+		msg.ShowModal();
+		return;
+	}
+
+	if (fsize == 0)
+	{
+		wxMessageDialog msg(this, wxT("DFU file is empty."), wxT("Error"), wxOK | wxSTAY_ON_TOP | wxCENTRE | wxICON_ERROR);
+		msg.ShowModal();
+		fclose(f);
+		return;
+	}
+
+	if (fseek(f, 0, SEEK_SET) != 0)
+	{
+		fclose(f);
+		wxMessageDialog msg(this, wxT("Cannot open DFU file."), wxT("Error"), wxOK | wxSTAY_ON_TOP | wxCENTRE | wxICON_ERROR);
+		msg.ShowModal();
+		return;
+	}
+	
+	mFirmwareImage.resize(fsize);
+
+	if (fread(mFirmwareImage.data(), fsize, 1, f) != 1)
+	{
+		fclose(f);
+		wxMessageDialog msg(this, wxT("Cannot read DFU file."), wxT("Error"), wxOK | wxSTAY_ON_TOP | wxCENTRE | wxICON_ERROR);
+		msg.ShowModal();
+		return;
+	}
+
+	fclose(f);
+
+	mFirmwareVersionBcd = Powermon::checkFirmwareImage(mFirmwareImage.data(), mFirmwareImage.size(), mPowermon.getLastDeviceInfo().hardware_revision_bcd);
+	if (mFirmwareVersionBcd == 0)
+	{
+		wxMessageDialog msg(this, wxT("Invalid DFU file."), wxT("Error"), wxOK | wxSTAY_ON_TOP | wxCENTRE | wxICON_ERROR);
+		msg.ShowModal();
+		return;
+	}
+
+	wxMessageDialog msg(this, wxT("You are about to update the firmware in your PowerMon device. \n"
+		"Do not disconnect the power, sit back and relax."), 
+		wxT("Confirmation"), wxOK | wxCANCEL | wxICON_QUESTION | wxSTAY_ON_TOP | wxCENTRE);
+
+	if (msg.ShowModal() == wxID_OK)
+		UpdateFirmware();
+}
+#endif
+
+
 void GuiAbout::OnGuiEvent(GuiEvent &event)
 {
 	event.process();
@@ -191,4 +274,8 @@
 
 EVT_BUTTON(ID_BUTTON_UPDATE, GuiAbout::OnButtonUpdateClicked)
 
+#ifdef DEBUG
+EVT_BUTTON(ID_BUTTON_UPDATE_FROM_FILE, GuiAbout::OnButtonUpdateFromFileClicked)
+#endif
+
 END_EVENT_TABLE()
diff --git a/gui/gui_about.h b/gui/gui_about.h
index b536a39..eda432f 100644
--- a/gui/gui_about.h
+++ b/gui/gui_about.h
@@ -36,6 +36,9 @@
 	enum
 	{
 		ID_BUTTON_UPDATE = wxID_HIGHEST + 1,
+#ifdef DEBUG
+		ID_BUTTON_UPDATE_FROM_FILE
+#endif
 	};
 
 	Powermon &mPowermon;
@@ -45,7 +48,13 @@
 	
 	wxStaticText* mStatusStatic;
 	
-	wxButton *mUpdateButton;
+	wxButton* mUpdateButton;
+
+#ifdef DEBUG
+	wxButton* mUpdateFromFileButton;
+	
+	void OnButtonUpdateFromFileClicked(wxCommandEvent &event);
+#endif
 
 	void OnButtonUpdateClicked(wxCommandEvent &event);
 	void OnClose(wxCloseEvent &event);