Run Time error 6 Overflow

[mlrucci]

Good morning, I am running MS access 64 bit. I have a list based on a qry to detect duplicates. I have code that will remove duplicates. For calculation/QC purposes, I want to show the number of rows that are duplicates. When opening the form, I get run-time error 6 overflow. The table has >160,000 records. I have no problems running the code with 90,000 records. My error is on the line of ListRows = .ListCount in the code below. Any ideas?

Private Sub CountItemsCommand()
Dim lstDups As Control
Set lstDups = Me.lstDups
Dim ListRows As Integer
ListRows = 0
    With lstDups
        If .ListCount > 0 Then
            ListRows = .ListCount
        Else
        'Exit Sub
        End If
    End With
Me.txtLstCount = ListRows
Set lstDups = Nothing
End Sub

[davegri]

First thing I would try:

Dim ListRows as Long

[mlrucci]

Worked like a charm. Can you explain why?

[davegri]

Worked like a charm. Can you explain why?

The maximum value of the integer type is 32767, while long is 2,147,483,647.