diff --git a/client/config_init.c b/client/config_init.c
index a87fb869..77ad1c24 100644
--- a/client/config_init.c
+++ b/client/config_init.c
@@ -2206,6 +2206,8 @@ usage(void)
       "                             packet (e.g. '123.2.3.4').  If \n"
       " -D, --destination           Specify the hostname or IP address of the\n"
       "                             fwknop server.\n"
+      " --use-hmac                  Add an HMAC to the outbound SPA packet for\n"
+      "                             authenticated encryption.\n"
       " -h, --help                  Print this usage message and exit.\n"
       " -B, --save-packet           Save the generated packet data to the\n"
       "                             specified file.\n"
@@ -2245,9 +2247,9 @@ usage(void)
       "                             line args as the last time it was executed\n"
       "                             (args are read from the ~/.fwknop.run file).\n"
       " -G, --get-key               Load an encryption key/password from a file.\n"
-      "     --stdin                 Read the encryption key/password from stdin\n"      
+      "     --stdin                 Read the encryption key/password from stdin\n"
       "     --fd                    Specify the file descriptor to read the\n"
-      "                             encryption key/password from.\n"      
+      "                             encryption key/password from.\n"
       " -k, --key-gen               Generate SPA Rijndael + HMAC keys.\n"
       " -K, --key-gen-file          Write generated Rijndael + HMAC keys to a\n"
       "                             file\n"