diff --git a/tests/instances.tcl b/tests/instances.tcl
index 370d5e3a..5251ffa3 100644
--- a/tests/instances.tcl
+++ b/tests/instances.tcl
@@ -136,6 +136,7 @@ proc parse_options {} {
             puts "--single <pattern>      Only runs tests specified by pattern."
             puts "--pause-on-error        Pause for manual inspection on error."
             puts "--fail                  Simulate a test failure."
+            puts "--valgrind              Run with valgrind."
             puts "--help                  Shows this help."
             exit 0
         } else {