diff --git a/nixos/modules/services/continuous-integration/gocd-agent/default.nix b/nixos/modules/services/continuous-integration/gocd-agent/default.nix
index 36f6527ee47b..bc6c6d5a2582 100644
--- a/nixos/modules/services/continuous-integration/gocd-agent/default.nix
+++ b/nixos/modules/services/continuous-integration/gocd-agent/default.nix
@@ -36,7 +36,7 @@ in {
       };
 
       packages = mkOption {
-        default = [ pkgs.stdenv pkgs.jre config.programs.ssh.package pkgs.nix ];
+        default = [ pkgs.stdenv pkgs.jre pkgs.git config.programs.ssh.package pkgs.nix ];
         type = types.listOf types.package;
         description = ''
           Packages to add to PATH for the Go.CD agent process.
@@ -80,26 +80,26 @@ in {
         '';
       };
 
-      heapSize = mkOption {
+      initialJavaHeapSize = mkOption {
         default = "128m";
         type = types.str;
         description = ''
-          Specifies the java heap memory size for the Go.CD agent java process.
+          Specifies the initial java heap memory size for the Go.CD agent java process.
         '';
       };
 
-      maxMemory = mkOption {
+      maxJavaHeapMemory = mkOption {
         default = "256m";
         type = types.str;
         description = ''
-          Specifies the java maximum memory size for the Go.CD agent java process.
+          Specifies the java maximum heap memory size for the Go.CD agent java process.
         '';
       };
 
       startupOptions = mkOption {
         default = [
-          "-Xms${cfg.heapSize}"
-          "-Xmx${cfg.maxMemory}"
+          "-Xms${cfg.initialJavaHeapSize}"
+          "-Xmx${cfg.maxJavaHeapMemory}"
           "-Djava.io.tmpdir=/tmp"
           "-Dcruise.console.publish.interval=10"
           "-Djava.security.egd=file:/dev/./urandom"
diff --git a/nixos/tests/gocd-agent.nix b/nixos/tests/gocd-agent.nix
index d5ed0f65ab01..34d0a800d092 100644
--- a/nixos/tests/gocd-agent.nix
+++ b/nixos/tests/gocd-agent.nix
@@ -4,10 +4,15 @@
 #   3. GoCD agent is available on GoCD server using GoCD API
 #     3.1. https://api.go.cd/current/#get-all-agents
 
+let
+  serverUrl = "localhost:8153/go/api/agents";
+  header = "Accept: application/vnd./go.cd/v2+json";
+in
+
 import ./make-test.nix ({ pkgs, ...} : {
   name = "gocd-agent";
   meta = with pkgs.stdenv.lib.maintainers; {
-    maintainers = [ swarren83 ];
+    maintainers = [ grahamc swarren83 ];
   };
 
 nodes = {
@@ -29,6 +34,7 @@ nodes = {
     $gocd_agent->waitForUnit("gocd-server");
     $gocd_agent->waitForOpenPort("8153");
     $gocd_agent->waitForUnit("gocd-agent");
-    $gocd_agent->waitUntilSucceeds("curl -s -f localhost:8153/go/api/agents -H 'Accept: application/vnd.go.cd.v2+json'");
+    $gocd_agent->waitUntilSucceeds("curl -s -f ${serverUrl} -H '${header}' | awk -F \" '/\"uuid\":\s\"[a-zA-Z0-9]{8}-[a-zA-Z0-9]{4}-[a-zA-Z0-9]{4}-[a-zA-Z0-9]{4}-[a-zA-Z0-9]{12}/ {print $4}'");
+    $gocd_agent->waitUntilSucceeds("curl -s -f ${serverUrl} -H '${header}' | awk -F \" '/\"agent_state\":\s\"Idle\"/'");
   '';
 })
diff --git a/pkgs/development/tools/continuous-integration/gocd-agent/default.nix b/pkgs/development/tools/continuous-integration/gocd-agent/default.nix
index 170f07ca5c3d..94938c2626a5 100644
--- a/pkgs/development/tools/continuous-integration/gocd-agent/default.nix
+++ b/pkgs/development/tools/continuous-integration/gocd-agent/default.nix
@@ -2,19 +2,19 @@
 
 stdenv.mkDerivation rec {
   name = "gocd-agent-${version}-${rev}";
-  version = "16.5.0";
-  rev = "3305";
+  version = "16.6.0";
+  rev = "3590";
 
   src = fetchurl {
     url = "https://download.go.cd/binaries/${version}-${rev}/generic/go-agent-${version}-${rev}.zip";
-    sha256 = "2cb988d36ec747b2917f3be040b430f2a8289c07353a6b6bdc95bf741fa1ed97";
+    sha256 = "ee076c62b388a6ed88d5065f18a4a96cb0d3161f693c16f920d85886d295ff27";
   };
   meta = with stdenv.lib; {
     description = "A continuous delivery server specializing in advanced workflow modeling and visualization";
     homepage = http://www.go.cd;
     license = licenses.asl20;
     platforms = platforms.all;
-    maintainers = with maintainers; [ swarren83 ];
+    maintainers = with maintainers; [ grahamc swarren83 ];
   };
 
   buildInputs = [ unzip ];