diff --git a/Component-Modem.md b/Component-Modem.md
index 3feafb6..3749e2c 100644
--- a/Component-Modem.md
+++ b/Component-Modem.md
@@ -10,6 +10,8 @@ Callbacks:
   Returns whether the specified "port" is currently being listened on. Messages only trigger signals when they arrive on a port that is open.
 - `open(port: number): boolean`  
   Opens the specified port number for listening. Returns `true` if the port was opened, `false` if it was already open.
+- `close([port: number]): boolean`
+  Closes the specified port (default: all ports). Returns true if ports were closed.
 - `send(address: string, port: number[, ...]): boolean`  
   Sends a network message to the specified address. Returns `true` if the message was sent. This does *not* mean the message was received, only that it was sent. No port-sniffing for you.  
   Any additional arguments are passed along as data. These arguments must be basic types: nil, boolean, number and string values are supported, tables and functions are not. See [[the text API|API/Text]] for serialization of tables.