diff --git a/src/sakia/gui/mainwindow.py b/src/sakia/gui/mainwindow.py
index 9fa92233e6fb2200d9162d50d1c3f86f1b77d566..4cd0ddb6704e019826cbe99f057bcbde773d9024 100644
--- a/src/sakia/gui/mainwindow.py
+++ b/src/sakia/gui/mainwindow.py
@@ -79,7 +79,7 @@ class MainWindow(QObject):
 
         self.combo_referential = combo_referential
         self.combo_referential.setEnabled(False)
-        self.combo_referential.currentIndexChanged.connect(self.referential_changed)
+        self.combo_referential.currentIndexChanged[str].connect(self.referential_changed)
 
         self.homescreen = homescreen