diff --git a/lib/core/util.js b/lib/core/util.js
index <HASH>..<HASH> 100644
--- a/lib/core/util.js
+++ b/lib/core/util.js
@@ -47,12 +47,13 @@ function destroy (stream, err) {
   }
 }
 
+const KEEPALIVE_TIMEOUT_EXPR = /timeout=(\d+)s/
 function parseKeepAliveTimeout (headers) {
   for (let n = 0; n < headers.length; n += 2) {
     const key = headers[n + 0]
     if (key.length === 10 && key.toLowerCase() === 'keep-alive') {
-      const timeout = parseInt(headers[n + 1].split('timeout=', 2)[1])
-      return timeout ? timeout * 1000 : undefined
+      const m = headers[n + 1].match(KEEPALIVE_TIMEOUT_EXPR)
+      return m ? parseInt(m[1]) * 1000 : null
     }
   }
 }
perf: parseKeepAliveTimeout

The regex version is fastest.