--- a/scripts/viewer/dlb_cpu_usage.in
+++ b/scripts/viewer/dlb_cpu_usage.in
@@ -1,8 +1,8 @@
 #!/usr/bin/env python2
 
-import Tkinter as tk
-import ttk
-import tkMessageBox
+import tkinter as tk
+from tkinter import ttk
+from tkinter import messagebox
 import random
 
 import sys
@@ -46,7 +46,7 @@
 
     def start(self):
         if self.viewer.empty():
-            tkMessageBox.showinfo("Warning", "Add some process before starting")
+            messagebox.showinfo("Warning", "Add some process before starting")
         if self.viewer:
             self.viewer.start()
 
--- a/scripts/viewer/dlb_viewer.py.in
+++ b/scripts/viewer/dlb_viewer.py.in
@@ -3,11 +3,12 @@
 import time
 from collections import deque
 # GUI
-import Tkinter as tk
-import ttk
+import tkinter as tk
+from tkinter import ttk
 import progressmeter
 from matplotlib.figure import Figure, figaspect
-from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2TkAgg
+from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
+from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT
 #DLB
 import dlb_wrapper
 
@@ -39,7 +40,7 @@
         self.canvas.get_tk_widget().pack(side=tk.TOP, fill=tk.BOTH, expand=1)
 
         if self.debug:
-            self.toolbar = NavigationToolbar2TkAgg(self.canvas, self )
+            self.toolbar = NavigationToolbar2QT(self.canvas, self )
             self.toolbar.pack()
             self.toolbar.update()
 
--- a/scripts/viewer/progressmeter.py
+++ b/scripts/viewer/progressmeter.py
@@ -1,10 +1,10 @@
 #!/usr/bin/env python2
 
 '''Michael Lange <klappnase (at) freakmail (dot) de>
-The Meter class provides a simple progress bar widget for Tkinter.
+The Meter class provides a simple progress bar widget for tkinter.
 
 INITIALIZATION OPTIONS:
-The widget accepts all options of a Tkinter.Frame plus the following:
+The widget accepts all options of a tkinter.Frame plus the following:
 
     fillcolor -- the color that is used to indicate the progress of the
                  corresponding process; default is "orchid1".
@@ -18,22 +18,22 @@
     textcolor -- the color to use for the widget's text; default is "black".
 
 WIDGET METHODS:
-All methods of a Tkinter.Frame can be used; additionally there are two widget specific methods:
+All methods of a tkinter.Frame can be used; additionally there are two widget specific methods:
 
     get() -- returns a tuple of the form (value, text)
     set(value, text) -- updates the widget's value and the displayed text;
                         if value is omitted it defaults to 0.0 , text defaults to None .
 '''
 
-import Tkinter
+import tkinter
 
-class Meter(Tkinter.Frame):
+class Meter(tkinter.Frame):
     def __init__(self, master, width=300, height=20, bg='white', fillcolor='orchid1',\
                  value=0.0, text=None, font=None, textcolor='black', *args, **kw):
-        Tkinter.Frame.__init__(self, master, bg=bg, width=width, height=height, *args, **kw)
+        tkinter.Frame.__init__(self, master, bg=bg, width=width, height=height, *args, **kw)
         self._value = value
 
-        self._canv = Tkinter.Canvas(self, bg=self['bg'], width=self['width'], height=self['height'],\
+        self._canv = tkinter.Canvas(self, bg=self['bg'], width=self['width'], height=self['height'],\
                                     highlightthickness=0, relief='flat', bd=0)
         self._canv.pack(fill='both', expand=1)
         self._rect = self._canv.create_rectangle(0, 0, 0, self._canv.winfo_reqheight(), fill=fillcolor,\
@@ -84,7 +84,7 @@
         meter.set(value, 'Demo successfully finished')
 
 if __name__ == '__main__':
-    root = Tkinter.Tk(className='meter demo')
+    root = tkinter.Tk(className='meter demo')
     m = Meter(root, relief='ridge', bd=3)
     m.pack(fill='x')
     m.set(0.0, 'Starting demo...')