Disable/Enable Tabstrip on Multitab based on Checkbox value- EXCEL

I have a userform with a multitab containing 8 tabs. I require a user to use checkboxes on tab 6. I'm try to disable the user from selecting the next tab (tab 7) if Checkbox 1 and Checkbox 2 are left unchecked. They should only be able to access the next tab if they select one of the two checkboxes.

Private Sub TabStrip6_Change()
If Failed1.Value = False And Passed1.Value = False Then
Me.MultiPage1.Pages(7).Enabled = False
End Sub

I can't quite get the code to work the way I want it to. Any help would be greatly appreciated.