diff --git a/docs/labwc-config.5.scd b/docs/labwc-config.5.scd
index 240f7043..dec027dc 100644
--- a/docs/labwc-config.5.scd
+++ b/docs/labwc-config.5.scd
@@ -244,7 +244,8 @@ this is for compatibility with Openbox.
 *<core><hdr>* [yes|no]
 	Automatically enable HDR support on outputs when configuring them,
 	where supported by the particular output device and display. Default
-	is no.
+	is no. Additionally requires the Vulkan backend. Can be set via
+	`WLR_RENDERER=vulkan` in `~/.config/labwc/enviornment`.
 
 *<core><reuseOutputMode>* [yes|no]
 	Try to re-use the existing output mode (resolution / refresh rate).