diff --git a/tests/functional/aws-node-sdk/test/support/config.js b/tests/functional/aws-node-sdk/test/support/config.js
index 28bc1cc9ba..c6065543c9 100644
--- a/tests/functional/aws-node-sdk/test/support/config.js
+++ b/tests/functional/aws-node-sdk/test/support/config.js
@@ -30,6 +30,18 @@ const DEFAULT_GLOBAL_OPTIONS = {
 // timeout.
 const REQUEST_TIMEOUT = 30000;
 
+// Idle timeout for pooled keep-alive sockets, which must stay below the
+// server's own keep-alive timeout. Node's HTTP server closes idle keep-alive
+// connections after 5s and advertises that as `Keep-Alive: timeout=5`, but the
+// agent only acts on the hint when it already has a non-zero timeout of its own
+// (`agentTimeout = this.options.timeout || 0`, and the hint can only lower an
+// existing value). Without one, the agent keeps pooled sockets forever and
+// eventually writes to connections the server has already closed, which
+// surfaces as ECONNRESET ("socket hang up"). This only ever destroys sockets
+// sitting in the free pool: an in-flight request is governed by
+// REQUEST_TIMEOUT, which the SDK applies to the socket for its duration.
+const AGENT_IDLE_TIMEOUT = 4000;
+
 const DEFAULT_MEM_OPTIONS = {
     endpoint: `${transport}://127.0.0.1:8000`,
     port: 8000,
@@ -43,6 +55,7 @@ const DEFAULT_MEM_OPTIONS = {
             maxSockets: 200,
             keepAlive: true,
             keepAliveMsecs: 1000,
+            timeout: AGENT_IDLE_TIMEOUT,
         }),
     }),
 };
@@ -57,6 +70,7 @@ const DEFAULT_AWS_OPTIONS = {
             maxSockets: 200,
             keepAlive: true,
             keepAliveMsecs: 1000,
+            timeout: AGENT_IDLE_TIMEOUT,
         }),
     }),
 };