diff --git a/README.md b/README.md
index c1f0bd36..b1a04323 100644
--- a/README.md
+++ b/README.md
@@ -81,6 +81,7 @@ The `DXVK_HUD` environment variable controls a HUD which can display the framera
 - `pipelines`: Shows the total number of graphics and compute pipelines.
 - `memory`: Shows the amount of device memory allocated and used.
 - `version`: Shows DXVK version.
+- `api`: Shows the D3D feature level used by the application. Does not work correctly for D3D10 at the moment.
 
 Additionally, `DXVK_HUD=1` has the same effect as `DXVK_HUD=devinfo,fps`, and `DXVK_HUD=full` enables all available HUD elements.