diff --git a/usr.bin/du/tests/du_test.sh b/usr.bin/du/tests/du_test.sh
index 92a26deae02b..1c283b58fef4 100755
--- a/usr.bin/du/tests/du_test.sh
+++ b/usr.bin/du/tests/du_test.sh
@@ -46,7 +46,7 @@ H_flag_body()
 {
 	local paths1='testdir/A/B testdir/A testdir/C testdir'
 	local paths2='testdir/C/B testdir/C'
-	local lineprefix="^[0-9]+$(printf "\t")"
+	local lineprefix=$'^[0-9]+\t'
 	local sep="\$\n${lineprefix}"
 
 	atf_check mkdir testdir