diff --git a/specs/HubProtocol.md b/specs/HubProtocol.md
index dae7d95f75..cd9523de03 100644
--- a/specs/HubProtocol.md
+++ b/specs/HubProtocol.md
@@ -105,7 +105,7 @@ On the Caller side, the user code which performs the invocation indicates how it
 
 An Invocation is only considered completed when the `Completion` message is received. Receiving **any** message using the same `Invocation ID` after a `Completion` message has been received for that invocation is considered a protocol error and the recipient may immediately terminate the connection.
 
-If a Callee is going to stream results, it **MUST** send each individual result in a separate `StreamItem` message, and complete the invocation with a `Completion`. If the Callee is going to return a single result, it **MUST** not send any `StreamItem` messages, and **MUST** send the single result in a `Completion` message. If the Callee receives an `Invocation` message for a method that would yield multiple results or the Callee receives a `StreamInvocationMessage` for a method that would return a single result it **MUST** complete the invocation with a `Completion` message containing an error.
+If a Callee is going to stream results, it **MUST** send each individual result in a separate `StreamItem` message, and complete the invocation with a `Completion`. If the Callee is going to return a single result, it **MUST** not send any `StreamItem` messages, and **MUST** send the single result in a `Completion` message. If the Callee receives an `Invocation` message for a method that would yield multiple results or the Callee receives a `StreamInvocation` message for a method that would return a single result it **MUST** complete the invocation with a `Completion` message containing an error.
 
 ## Errors