Highlighting duplicate values in a column in OpenOffice Calc

I'm using a Linux machine and I've been trying to find an equivalent to excel's

"highlight Cell Rules > Duplicate Values" 

formula that I can use to color cells that have duplicates on the column in OpenOffice Calc. I've already found and tried

COUNTIF(A$1:A$15; A1)>1 

as a formula but this doesn't work on every single item in the column vs every single other one.