Drop Down Value Shows the Key and not Display Value

Hey Guys,

We are trying to have a drop down value on a lead be transferred to a text field on an account during lead conversion. Our code is written below. Naics_sector is the account field and industry_sector is the drop down field on the lead. The conversion works, but only the drop down key is being brought into the text field and not the actually display value. How can we get the display value of the drop down brought into the text field? Thanks!

'fieldMapping' =>
array (

'naics_sector_c' => 'industry_sector_c',