diff --git a/gramps/gui/navigator.py b/gramps/gui/navigator.py
index 81dc41735..5de121605 100644
--- a/gramps/gui/navigator.py
+++ b/gramps/gui/navigator.py
@@ -292,10 +292,18 @@ class Navigator(object):
 # Functions
 #
 #-------------------------------------------------------------------------
-def cb_menu_position(menu, button):
+def cb_menu_position(*args):
     """
     Determine the position of the popup menu.
     """
+    # takes two argument: menu, button
+    if len(args) == 2:
+        menu = args[0]
+        button = args[1]
+    # broken introspection can't handle MenuPositionFunc annotations corectly
+    else:
+        menu = args[0]
+        button = args[3]
     ret_val, x_pos, y_pos = button.get_window().get_origin()
     x_pos += button.get_allocation().x
     y_pos += button.get_allocation().y + button.get_allocation().height
diff --git a/gramps/gui/views/tags.py b/gramps/gui/views/tags.py
index 43a72664c..1485ce7cc 100644
--- a/gramps/gui/views/tags.py
+++ b/gramps/gui/views/tags.py
@@ -276,10 +276,19 @@ class Tags(DbGUIElement):
                 view.add_tag(trans, object_handle, tag_handle)
         status.end()
 
-def cb_menu_position(menu, button):
+def cb_menu_position(*args):
     """
     Determine the position of the popup menu.
     """
+    # takes two argument: menu, button
+    if len(args) == 2:
+        menu = args[0]
+        button = args[1]
+    # broken introspection can't handle MenuPositionFunc annotations corectly
+    else:
+        menu = args[0]
+        button = args[3]
+
     ret_val, x_pos, y_pos = button.get_window().get_origin()
     x_pos += button.get_allocation().x
     y_pos += button.get_allocation().y + button.get_allocation().height
diff --git a/gramps/gui/widgets/grampletbar.py b/gramps/gui/widgets/grampletbar.py
index ae51dd520..649c88fcd 100644
--- a/gramps/gui/widgets/grampletbar.py
+++ b/gramps/gui/widgets/grampletbar.py
@@ -730,10 +730,18 @@ class TabLabel(Gtk.Box):
         else:
             self.closebtn.hide()
 
-def cb_menu_position(menu, button):
+def cb_menu_position(*args):
     """
     Determine the position of the popup menu.
     """
+    # takes two argument: menu, button
+    if len(args) == 2:
+        menu = args[0]
+        button = args[1]
+    # broken introspection can't handle MenuPositionFunc annotations corectly
+    else:
+        menu = args[0]
+        button = args[3]
     ret_val, x_pos, y_pos = button.get_window().get_origin()
     x_pos += button.get_allocation().x
     y_pos += button.get_allocation().y + button.get_allocation().height
diff --git a/gramps/plugins/sidebar/dropdownsidebar.py b/gramps/plugins/sidebar/dropdownsidebar.py
index 88f6330d7..dd5edf58a 100644
--- a/gramps/plugins/sidebar/dropdownsidebar.py
+++ b/gramps/plugins/sidebar/dropdownsidebar.py
@@ -205,10 +205,18 @@ class DropdownSidebar(BaseSidebar):
             self.viewmanager.notebook.set_current_page(page_no)
         self.__handlers_unblock()
 
-def cb_menu_position(menu, button):
+def cb_menu_position(*args):
     """
     Determine the position of the popup menu.
     """
+    # takes two argument: menu, button
+    if len(args) == 2:
+        menu = args[0]
+        button = args[1]
+    # broken introspection can't handle MenuPositionFunc annotations corectly
+    else:
+        menu = args[0]
+        button = args[3]
     ret_val, x_pos, y_pos = button.get_window().get_origin()
     x_pos += button.get_allocation().x
     y_pos += button.get_allocation().y + button.get_allocation().height
diff --git a/gramps/plugins/sidebar/expandersidebar.py b/gramps/plugins/sidebar/expandersidebar.py
index 4cdd4beb4..af538d0fd 100644
--- a/gramps/plugins/sidebar/expandersidebar.py
+++ b/gramps/plugins/sidebar/expandersidebar.py
@@ -218,10 +218,18 @@ class ExpanderSidebar(BaseSidebar):
             self.viewmanager.notebook.set_current_page(page_no)
         self.__handlers_unblock()
 
-def cb_menu_position(menu, button):
+def cb_menu_position(*args):
     """
     Determine the position of the popup menu.
     """
+    # takes two argument: menu, button
+    if len(args) == 2:
+        menu = args[0]
+        button = args[1]
+    # broken introspection can't handle MenuPositionFunc annotations corectly
+    else:
+        menu = args[0]
+        button = args[3]
     ret_val, x_pos, y_pos = button.get_window().get_origin()
     x_pos += button.get_allocation().x
     y_pos += button.get_allocation().y + button.get_allocation().height