diff --git a/Documentation/devicetree/bindings/pwm/mediatek,pwm-disp.yaml b/Documentation/devicetree/bindings/pwm/mediatek,pwm-disp.yaml
index afcdeed4e88a..bc813fe74fab 100644
--- a/Documentation/devicetree/bindings/pwm/mediatek,pwm-disp.yaml
+++ b/Documentation/devicetree/bindings/pwm/mediatek,pwm-disp.yaml
@@ -52,6 +52,9 @@ properties:
       - const: main
       - const: mm
 
+  power-domains:
+    maxItems: 1
+
 required:
   - compatible
   - reg