diff --git a/sciotest/main.cpp b/sciotest/main.cpp
index 7affbec..9c30ca1 100644
--- a/sciotest/main.cpp
+++ b/sciotest/main.cpp
@@ -22,6 +22,7 @@ using namespace std;
 void print_help() {
     std::cout << "usage: sciotest [-h][-v][-t TEST_ID]\n";
     std::cout << "  -h, --help    show this help text and exit\n";
+    std::cout << "  -t, --test    perform test with given ID\n";
     std::cout << "  -v, --version show version number and exit\n";
 }