diff --git a/pyfda/plot_widgets/mpl_widget.py b/pyfda/plot_widgets/mpl_widget.py
index 2aad6ac52..da5e16c8a 100644
--- a/pyfda/plot_widgets/mpl_widget.py
+++ b/pyfda/plot_widgets/mpl_widget.py
@@ -29,7 +29,7 @@
 
 from pyfda.libs.compat import (QtCore, QWidget, QLabel, pyqtSignal, pyqtSlot,
                       QSizePolicy, QIcon, QImage, QVBoxLayout,
-                      QInputDialog, FigureCanvas, NavigationToolbar)
+                      QInputDialog, FigureCanvas, NavigationToolbar, MplToolbar)
 
 from pyfda import pyfda_rc
 import pyfda.filterbroker as fb