diff --git a/Sources/AWSLambdaRuntimeCore/HTTPClient.swift b/Sources/AWSLambdaRuntimeCore/HTTPClient.swift
index 4945b439..f3d073d3 100644
--- a/Sources/AWSLambdaRuntimeCore/HTTPClient.swift
+++ b/Sources/AWSLambdaRuntimeCore/HTTPClient.swift
@@ -27,6 +27,8 @@ internal final class HTTPClient {
     private var state = State.disconnected
     private var executing = false
 
+    private static let headers = HTTPHeaders([("user-agent", "Swift-Lambda/Unknown")])
+
     init(eventLoop: EventLoop, configuration: Lambda.Configuration.RuntimeEngine) {
         self.eventLoop = eventLoop
         self.configuration = configuration
@@ -37,6 +39,7 @@ internal final class HTTPClient {
         self.execute(Request(targetHost: self.targetHost,
                              url: url,
                              method: .GET,
+                             headers: HTTPClient.headers,
                              timeout: timeout ?? self.configuration.requestTimeout))
     }
 
@@ -44,6 +47,7 @@ internal final class HTTPClient {
         self.execute(Request(targetHost: self.targetHost,
                              url: url,
                              method: .POST,
+                             headers: HTTPClient.headers,
                              body: body,
                              timeout: timeout ?? self.configuration.requestTimeout))
     }