diff --git a/docs/api/protocol.md b/docs/api/protocol.md
index 1a6a0f8532..4d19869cea 100644
--- a/docs/api/protocol.md
+++ b/docs/api/protocol.md
@@ -267,7 +267,7 @@ Unregisters the custom protocol of `scheme`.
 
 * `scheme` String
 * `callback` Function
-  * `error` Error
+  * `handled` Boolean
 
 The `callback` will be called with a boolean that indicates whether there is
 already a handler for `scheme`.