diff --git a/prism/etc/scripts/prism-auto b/prism/etc/scripts/prism-auto
index 589a3fcb..08d5b0b0 100755
--- a/prism/etc/scripts/prism-auto
+++ b/prism/etc/scripts/prism-auto
@@ -638,7 +638,7 @@ parser.add_option("--test-all", action="store_true", dest="testAll", default=Fal
 parser.add_option("--no-renaming", action="store_true", dest="noRenaming", default=False, help="Don't rename files to be exported")
 parser.add_option("--debug", action="store_true", dest="debug", default=False, help="Enable debug mode: display debugging info")
 parser.add_option("--echo-full", action="store_true", dest="echoFull", default=False, help="An expanded version of -e/--echo")
-parser.add_option("--models-filename", dest="modelsFilename", default="models", help="The name of the optional 'models' file in directories, storing a list of models and parameters [default=models]")
+parser.add_option("--models-filename", dest="modelsFilename", metavar="X", default="models", help="Read in list of models/parameters for a directory from file X, if present [default=models]")
 parser.add_option("--no-export-tests", action="store_true", dest="noExportTests", default=False, help="Don't check exported files when in test mode")
 parser.add_option("--colour", dest="colourEnabled", metavar="X", type="choice", choices=["yes","no","auto"], default="auto", help="Whether to colour test results: yes, no, auto (yes iff in terminal mode) [default=auto]")
 (options, args) = parser.parse_args()