diff --git a/doc/v4l2.md b/doc/v4l2.md
index 54272b2b..ac1e3540 100644
--- a/doc/v4l2.md
+++ b/doc/v4l2.md
@@ -38,6 +38,13 @@ v4l2-ctl --list-devices
 ls /dev/video*
 ```
 
+If a loopback device was not created automatically, you can make a new one:
+
+```
+# requires v4l2loopback-utils package
+sudo v4l2loopback-ctl add
+```
+
 To start `scrcpy` using a v4l2 sink:
 
 ```bash