diff --git a/tests/README b/tests/README
index ae8ff25cc4..834be63a5e 100644
--- a/tests/README
+++ b/tests/README
@@ -43,6 +43,7 @@ The cURL Test Suite
   diff (when a test fails, a diff is shown)
   stunnel (for HTTPS and FTPS tests)
   OpenSSH or SunSSH (for SCP, SFTP and SOCKS4/5 tests)
+  nghttpx (for HTTP/2 tests)
 
  1.2 Port numbers used by test servers