diff --git a/scripts/mbusb_gui.py b/scripts/mbusb_gui.py
index c03778b8..63606ca1 100644
--- a/scripts/mbusb_gui.py
+++ b/scripts/mbusb_gui.py
@@ -320,7 +320,7 @@ def ui_update_persistence(self):
             self.ui.slider_persistence.setEnabled(True)
             self.ui.slider_persistence.setTickInterval(10)
             self.ui.slider_persistence.setSingleStep(10)
-            self.ui.slider_persistence.setMaximum(config.persistence_max_size / 1024 / 1024)
+            self.ui.slider_persistence.setMaximum(int(config.persistence_max_size / 1024 / 1024))
         #             log("===== getMaximum = " + self.ui.slider_persistence.getMaximum()
         else:
             self.ui.label_persistence_value.setEnabled(False)