diff --git a/tools/testing/selftests/zram/zram.sh b/tools/testing/selftests/zram/zram.sh
index 20de9a761269..683a292e3290 100755
--- a/tools/testing/selftests/zram/zram.sh
+++ b/tools/testing/selftests/zram/zram.sh
@@ -1,15 +1,7 @@
 #!/bin/bash
 TCID="zram.sh"
 
-check_prereqs()
-{
-	local msg="skip all tests:"
-
-	if [ $UID != 0 ]; then
-		echo $msg must be run as root >&2
-		exit 0
-	fi
-}
+. ./zram_lib.sh
 
 run_zram () {
 echo "--------------------"
diff --git a/tools/testing/selftests/zram/zram_lib.sh b/tools/testing/selftests/zram/zram_lib.sh
index 424e68ed1487..f6a9c73e7a44 100755
--- a/tools/testing/selftests/zram/zram_lib.sh
+++ b/tools/testing/selftests/zram/zram_lib.sh
@@ -23,8 +23,9 @@ trap INT
 check_prereqs()
 {
 	local msg="skip all tests:"
+	local uid=$(id -u)
 
-	if [ $UID != 0 ]; then
+	if [ $uid -ne 0 ]; then
 		echo $msg must be run as root >&2
 		exit 0
 	fi