diff --git a/README.md b/README.md
index 16b982f..d98e6bd 100644
--- a/README.md
+++ b/README.md
@@ -44,6 +44,7 @@ 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)
 ```
 
@@ -168,6 +169,8 @@ on `bc` and `column` commands.
 
   * [x] Show progress when more than one request (`-n 2` etc) option is set
 
+	* [x] Allow custom options to be passed to curl (use the `-o` option)
+
   * [ ] Sort output by fastest TTFB when multiple URLs are supplied
 
   * [ ] Colour code the `TTFB:` figure in the standard response, according to the speed of the response.
diff --git a/ttfb b/ttfb
index 99a8aa7..d1b8350 100755
--- a/ttfb
+++ b/ttfb
@@ -92,7 +92,7 @@ median() {
 }
 
 show_usage() {
-  echo -e "Usage: ttfb [options] url [url...]\n\t-d debug\n\t-l <log file> (infers -d) log response headers. Defaults to ./curl.log\n\t-n <number> of times to test time to first byte\n\t-v verbose output. Show response breakdown (DNS lookup, TLS handshake etc)" >&2
+  echo -e "Usage: ttfb [options] url [url...]\n\t-d debug\n\t-l <log file> (infers -d) log response headers. Defaults to ./curl.log\n\t-n <number> of times to test time to first byte\n\t-o <option> pass options to curl (e.g. -o \"-k\" will make curl ignore invalid certificates)\n\t-v verbose output. Show response breakdown (DNS lookup, TLS handshake etc)" >&2
 }
 
 # defaults