diff --git a/tests/zfs-tests/tests/functional/cli_root/zhack/zhack_metaslab_leak.ksh b/tests/zfs-tests/tests/functional/cli_root/zhack/zhack_metaslab_leak.ksh
index cc72d6313..0d2a39be6 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zhack/zhack_metaslab_leak.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zhack/zhack_metaslab_leak.ksh
@@ -64,7 +64,7 @@ log_must zpool import $TESTPOOL
 
 alloc2=$(zpool get -Hpo value alloc $TESTPOOL)
 
-[[ $((alloc * 1.05)) -gt $alloc2 ]] && [[ $alloc -lt $alloc2 ]] || \
+within_percent $alloc $alloc2 98 || 
 	log_fail "space usage changed too much: $alloc to $alloc2"
 
 log_pass "zhack metaslab leak behaved correctly"