diff --git a/README.md b/README.md
index da1f469..e3bec22 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,7 @@ Usage: ttfb [options] url [url...]
 	-d debug
 	-l <log file> (infers -d) log response headers. Defaults to ./curl.log
 	-n <number> of times to test time to first byte
+	-o <option> pass options to curl (e.g. -o "-k" will make curl ignore invalid certificates)
 	-v verbose output. Show response breakdown (DNS lookup, TLS handshake etc)
 ```
 
diff --git a/ttfb b/ttfb
index d1b8350..6841194 100755
--- a/ttfb
+++ b/ttfb
@@ -11,6 +11,7 @@
 #   -d debug
 #   -l <log file> (infers -d) log response headers. Defaults to ./curl.log
 #   -n <number> of times to test time to first byte
+#   -o <option> pass options to curl (e.g. -o "-k" will make curl ignore invalid certificates)
 #   -v verbose output. Show request breakdown during -n calls
 #
 # Examples: