diff --git a/tests/zfs-tests/tests/functional/trim/trim.kshlib b/tests/zfs-tests/tests/functional/trim/trim.kshlib
index 41f80c065d19..b0bea78629c9 100644
--- a/tests/zfs-tests/tests/functional/trim/trim.kshlib
+++ b/tests/zfs-tests/tests/functional/trim/trim.kshlib
@@ -38,10 +38,12 @@ function get_trim_io
 	# Sum the ind or agg columns of the trim request size histogram.
 	case "$type" in
 	"ind")
+		log_must zpool iostat -pr $pool $vdev
 		zpool iostat -pr $pool $vdev |
 		    awk '$1 ~ /[0-9].*/ { sum += $12 } END { print sum }'
 		;;
 	"agg")
+		log_must zpool iostat -pr $pool $vdev
 		zpool iostat -pr $pool $vdev |
 		    awk '$1 ~ /[0-9].*/ { sum += $13 } END { print sum }'
 		;;