--- a/src/tools/nona.cpp
+++ b/src/tools/nona.cpp
@@ -94,6 +94,7 @@
     << "      -z         set compression type." << std::endl
     << "                  Possible options for tiff output:" << std::endl
     << "                   NONE      no compression" << std::endl
+    << "                   PACKBITS  packbits compression" << std::endl
     << "                   LZW       lzw compression" << std::endl
     << "                   DEFLATE   deflate compression" << std::endl
     << std::endl;