diff --git a/README.md b/README.md
index 8f457c1..4066bcb 100644
--- a/README.md
+++ b/README.md
@@ -37,13 +37,13 @@ Running ioctl's inside containers is a little tricky.
 Assuming we've already `insmod` the module above:
 
 ```shell
-sudo docker run -it --rm -v $(pwd)/helloctl/helloctl:/usr/bin/helloctl -v /dev/helloctl:/dev/helloctl fedora /usr/bin/helloctl
+sudo docker run -it --rm -v $(pwd)/helloctl/helloctl:/usr/bin/helloctl:ro -v /dev/helloctl:/dev/helloctl:ro fedora /usr/bin/helloctl
 ```
 
 You'll get a failure `Could not open /dev/helloctl`
 
 ```shell
-sudo docker run -it --rm -v $(pwd)/helloctl/helloctl:/usr/bin/helloctl -v /dev/helloctl:/dev/helloctl --privileged fedora /usr/bin/helloctl
+sudo docker run -it --rm -v $(pwd)/helloctl/helloctl:/usr/bin/helloctl:ro -v /dev/helloctl:/dev/helloctl:ro --privileged fedora /usr/bin/helloctl
 ```
 
 Now `dmesg | tail` will reflect the command ran successfully.