How do I apply a SumIf Formula in a VBA Sub? Getting Error 1004

Question

I am trying to create a Sub that places a SUMIF formula in a cell. I have reduced the problem to a simple setup:

Private Sub CommandButton1_Click()
Cells(2, 3).Formula = "=SUMIF(A1:A5;D1;B1:B5)"
End Sub

I get a 1004 Error.

I can run the same code but with the SUM function instead:

"=SUM(B1:B5)"

This does not produce an error. Thus I suspect the semicolons in my formula.