diff --git a/instrumentation/netty/netty-4.0/javaagent/src/test/groovy/Netty40ClientSslTest.groovy b/instrumentation/netty/netty-4.0/javaagent/src/test/groovy/Netty40ClientSslTest.groovy
index 632da29467..e3bbdb15e8 100644
--- a/instrumentation/netty/netty-4.0/javaagent/src/test/groovy/Netty40ClientSslTest.groovy
+++ b/instrumentation/netty/netty-4.0/javaagent/src/test/groovy/Netty40ClientSslTest.groovy
@@ -50,7 +50,7 @@ class Netty40ClientSslTest extends AgentInstrumentationSpecification {
 
   def cleanupSpec() {
     server.stop().get(10, TimeUnit.SECONDS)
-    eventLoopGroup.shutdownGracefully().sync()
+    eventLoopGroup.shutdownGracefully()
   }
 
   def "should fail SSL handshake"() {
diff --git a/instrumentation/netty/netty-4.1/javaagent/src/test/groovy/Netty41ClientSslTest.groovy b/instrumentation/netty/netty-4.1/javaagent/src/test/groovy/Netty41ClientSslTest.groovy
index 94bedaffe9..c521e22cf6 100644
--- a/instrumentation/netty/netty-4.1/javaagent/src/test/groovy/Netty41ClientSslTest.groovy
+++ b/instrumentation/netty/netty-4.1/javaagent/src/test/groovy/Netty41ClientSslTest.groovy
@@ -52,7 +52,7 @@ class Netty41ClientSslTest extends AgentInstrumentationSpecification {
 
   def cleanupSpec() {
     server.stop().get(10, TimeUnit.SECONDS)
-    eventLoopGroup.shutdownGracefully().sync()
+    eventLoopGroup.shutdownGracefully()
   }
 
   def "should fail SSL handshake"() {