diff --git a/era/era_invalidate.cc b/era/era_invalidate.cc
index e9a4ca1..76eaadd 100644
--- a/era/era_invalidate.cc
+++ b/era/era_invalidate.cc
@@ -199,7 +199,6 @@ era_invalidate_cmd::usage(std::ostream &out) const
 	    << "  {-h|--help}\n"
 	    << "  {-o <xml file>}\n"
 	    << "  {--metadata-snapshot}\n"
-	    << "  {--written-since}\n"
 	    << "  {-V|--version}" << endl;
 }