diff --git a/Tests/GRPCInterceptorsTests/TracingTestsUtilities.swift b/Tests/GRPCInterceptorsTests/TracingTestsUtilities.swift
index ffed5213a..ead6e58d3 100644
--- a/Tests/GRPCInterceptorsTests/TracingTestsUtilities.swift
+++ b/Tests/GRPCInterceptorsTests/TracingTestsUtilities.swift
@@ -149,6 +149,7 @@ extension ServiceContext {
   }
 }
 
+@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
 struct TestWriter<WriterElement>: RPCWriterProtocol {
   typealias Element = WriterElement