diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
index aefb63949619..9d92d42140f2 100644
--- a/Documentation/devicetree/bindings/net/stmmac.txt
+++ b/Documentation/devicetree/bindings/net/stmmac.txt
@@ -32,6 +32,8 @@ Optional properties:
 - resets: Should contain a phandle to the STMMAC reset signal, if any
 - reset-names: Should contain the reset signal name "stmmaceth", if a
 	reset phandle is given
+- max-frame-size:	Maximum Transfer Unit (IEEE defined MTU), rather
+			than the maximum frame size.
 
 Examples:
 
@@ -42,5 +44,6 @@ Examples:
 		interrupts = <24 23>;
 		interrupt-names = "macirq", "eth_wake_irq";
 		mac-address = [000000000000]; /* Filled in by U-Boot */
+		max-frame-size = <3800>;
 		phy-mode = "gmii";
 	};