diff --git a/Documentation/devicetree/usage-model.txt b/Documentation/devicetree/usage-model.txt
index dca90fe22a90c5d61c3cc0251326917a143e8929..ef9d06c9f8fde9341c3dc1926f83524fb7a47396 100644
--- a/Documentation/devicetree/usage-model.txt
+++ b/Documentation/devicetree/usage-model.txt
@@ -347,7 +347,7 @@ later), which will happily live at the base of the Linux /sys/devices
 tree.  Therefore, if a DT node is at the root of the tree, then it
 really probably is best registered as a platform_device.
 
-Linux board support code calls of_platform_populate(NULL, NULL, NULL)
+Linux board support code calls of_platform_populate(NULL, NULL, NULL, NULL)
 to kick off discovery of devices at the root of the tree.  The
 parameters are all NULL because when starting from the root of the
 tree, there is no need to provide a starting node (the first NULL), a