diff --git a/Libraries/ConnectMocks/MockBidirectionalStream.swift b/Libraries/ConnectMocks/MockBidirectionalStream.swift
index 1fc13657..f13d8299 100644
--- a/Libraries/ConnectMocks/MockBidirectionalStream.swift
+++ b/Libraries/ConnectMocks/MockBidirectionalStream.swift
@@ -23,6 +23,7 @@ import SwiftProtobuf
 /// or by subclassing the type and overriding functions such as `send()`.
 ///
 /// To return data over the stream, outputs can be specified using `init(outputs: ...)`.
+@available(iOS 13.0, *)
 open class MockBidirectionalStream<
     Input: SwiftProtobuf.Message,
     Output: SwiftProtobuf.Message
diff --git a/Libraries/ConnectMocks/MockClientOnlyStream.swift b/Libraries/ConnectMocks/MockClientOnlyStream.swift
index 09657ea7..48a9d447 100644
--- a/Libraries/ConnectMocks/MockClientOnlyStream.swift
+++ b/Libraries/ConnectMocks/MockClientOnlyStream.swift
@@ -22,6 +22,7 @@ import SwiftProtobuf
 /// or by subclassing the type and overriding functions such as `send()`.
 ///
 /// To return data over the stream, outputs can be specified using `init(outputs: ...)`.
+@available(iOS 13.0, *)
 open class MockClientOnlyStream<
     Input: SwiftProtobuf.Message,
     Output: SwiftProtobuf.Message
diff --git a/Libraries/ConnectMocks/MockServerOnlyStream.swift b/Libraries/ConnectMocks/MockServerOnlyStream.swift
index cec574b2..054490e4 100644
--- a/Libraries/ConnectMocks/MockServerOnlyStream.swift
+++ b/Libraries/ConnectMocks/MockServerOnlyStream.swift
@@ -23,6 +23,7 @@ import SwiftProtobuf
 /// or by subclassing the type and overriding functions such as `send()`.
 ///
 /// To return data over the stream, outputs can be specified using `init(outputs: ...)`.
+@available(iOS 13.0, *)
 open class MockServerOnlyStream<
     Input: SwiftProtobuf.Message,
     Output: SwiftProtobuf.Message