diff --git a/picom.sample.conf b/picom.sample.conf
index 898b1de..59255d0 100644
--- a/picom.sample.conf
+++ b/picom.sample.conf
@@ -321,11 +321,17 @@ use-damage = true;
 #
 # xrender-sync-fence = false
 
-# GLX backend: Use specified GLSL fragment shader for rendering window contents.
-# See `compton-default-fshader-win.glsl` and `compton-fake-transparency-fshader-win.glsl`
-# in the source tree for examples.
+# GLX backend: Use specified GLSL fragment shader for rendering window
+# contents. Read the man page for a detailed explanation of the interface.
 #
-# glx-fshader-win = ""
+# window-shader-fg = "default"
+
+# Use rules to set per-window shaders. Syntax is SHADER_PATH:PATTERN, similar
+# to opacity-rule. SHADER_PATH can be "default". This overrides window-shader-fg.
+#
+# window-shader-fg-rule = [
+#   "my_shader.frag:window_type != 'dock'"
+# ]
 
 # Force all windows to be painted with blending. Useful if you
 # have a glx-fshader-win that could turn opaque pixels transparent.