diff --git a/image_list.py b/image_list.py
index c80dffe..bce6405 100755
--- a/image_list.py
+++ b/image_list.py
@@ -41,7 +41,7 @@ def setup_options():
     parser.add_argument("--small",action="store_true",dest="searchsmall",default=False,
                      help="Return a list of small files, smaller than -m INT. This option will flip the 'Add new files' option. [%(default)s]")
     parser.add_argument("--similar",type=str,dest="similarity",default=None,
-                     help="Search list for similar images. Value 0-255 for similarity threshold. 0=high similarity")
+                     help="Search list for similar images. Value 0-255 for similarity threshold. 0=high similarity. If value is a filename, search similar to that image.")
     parser.add_argument("-x",action="append",dest="exclude",default=[],
                      help="Exclude folder name from the lists. This option may be issued several times")
     parser.add_argument('startpath', action="store",default='.', nargs='?')