--- a/src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/ConnectionPool.java	Mon Feb 05 11:54:03 2018 +0000
+++ b/src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/ConnectionPool.java	Mon Feb 05 11:57:50 2018 +0000
@@ -122,7 +122,7 @@
         return dbgTag;
     }
 
-    void start() {
+    synchronized void start() {
         assert !stopped : "Already stopped";
     }