diff --git a/guestfs-inspectd.c b/guestfs-inspectd.c
index 638591e..601bbc2 100644
--- a/guestfs-inspectd.c
+++ b/guestfs-inspectd.c
@@ -143,7 +143,7 @@ static void *worker_task(zsock_t *pipe, char *disk_path) {
 
 int main(int argc, char **argv) {
   if (argc < 2) {
-    printf("Usage: %s <disk-path> ...\n", argv[0]);
+    printf("Usage: %s <disk-path>:<name> ...\n", argv[0]);
     return EXIT_FAILURE;
   }