Conditional Formatting - change color for matching cell

I have two sheets, Sheet1 and Sheet2.

Sheet1 contains the following data:

abc

def

ghi

jkl

mno

pqr

stu

vwx

yz

Sheet2 contains the following:

abc

ghi

jkl

mno

pqr

yz

I want to apply conditional formatting in Sheet1 for matches in Sheet2, so that for each match, the cell's fill color is changed to, say green.

I select the entire range in Sheet1 and as a New Formatting Rule, choose Cell Value equal to = Sheet2!$A$2:$A$6

However, this throws the following error:

"This type of reference cannot be used in a Conditional Formatting formula.

Change the reference to a single cell, or use the reference with a worksheet function, such as =SUM(A1:E5)"

Any help here is greatly appreciated. Thanks.