diff --git a/zb-cleanup b/zb-cleanup
index 4b69990..825de43 100755
--- a/zb-cleanup
+++ b/zb-cleanup
@@ -1,7 +1,7 @@
 #!/bin/bash
 
 if [[ -z "$1" || -z "$2" ]] ; then
-	echo "usage: $0 <volume> <density>" >&2
+	echo "usage: $0 <zfs_object> <density>" >&2
 	exit 1
 fi
 
diff --git a/zb-snap b/zb-snap
index f8b6fd8..a1f4591 100755
--- a/zb-snap
+++ b/zb-snap
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 if [ -z "$1" ] ; then
-	echo "usage: $0 <zfs_volume>" >&2
+	echo "usage: $0 <zfs_object>" >&2
 	exit 1
 fi