diff --git a/client/pom.xml b/client/pom.xml
index c9e77a7a..4e94f162 100644
--- a/client/pom.xml
+++ b/client/pom.xml
@@ -38,6 +38,16 @@
       <groupId>org.apache.cxf</groupId>
       <artifactId>cxf-rt-transports-http-hc</artifactId>
       <version>${cxf.version}</version>
+      <exclusions>
+        <exclusion>
+          <groupId>org.apache.httpcomponents</groupId>
+          <artifactId>httpcore-nio</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>org.apache.httpcomponents</groupId>
+          <artifactId>httpasyncclient</artifactId>
+        </exclusion>
+      </exclusions>
     </dependency>
     <dependency>
       <groupId>org.apache.cxf</groupId>
@@ -51,6 +61,32 @@
       <scope>provided</scope>
     </dependency>
 
+    <!--
+        Exclusions (and then explicit dependencies below) required by cxf-rt-transports-http-hc. That tries to pull in
+        directly httpcore-nio 4.4.5 (which pulls in httpcore 4.4.5), and same for httpasyncclient. However, it also pulls
+        in httclient, which depends on httpcore 4.4.4. This causes maven-enforcer-plugin's dependencyConvergence to fail.
+    -->
+    <dependency>
+      <groupId>org.apache.httpcomponents</groupId>
+      <artifactId>httpcore-nio</artifactId>
+      <version>${httpcomponents.httpcore.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.httpcomponents</groupId>
+      <artifactId>httpasyncclient</artifactId>
+      <version>${httpcomponents.httpasyncclient.version}</version>
+      <exclusions>
+        <exclusion>
+          <groupId>org.apache.httpcomponents</groupId>
+          <artifactId>httpcore</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>org.apache.httpcomponents</groupId>
+          <artifactId>httpcore-nio</artifactId>
+        </exclusion>
+      </exclusions>
+    </dependency>
+
     <dependency>
       <groupId>com.squareup.okhttp3</groupId>
       <artifactId>mockwebserver</artifactId>
@@ -102,7 +138,6 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-dependency-plugin</artifactId>
-        <version>2.10</version>
         <executions>
           <execution>
             <id>unpack</id>
@@ -201,7 +236,6 @@
           <plugin>
             <groupId>org.apache.cxf</groupId>
             <artifactId>cxf-codegen-plugin</artifactId>
-            <version>${cxf.version}</version>
             <executions>
               <execution>
                 <id>generate-sources</id>
diff --git a/pom.xml b/pom.xml
index f580fba0..8e81d3b6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -61,10 +61,13 @@
     <includedTestGroups />
     <excludedTestGroups>Integration,Acceptance,Live,WIP</excludedTestGroups>
     <surefire.failIfNoSpecifiedTests>false</surefire.failIfNoSpecifiedTests>
-    <surefire.version>2.18.1</surefire.version>
-    <testng.version>6.8.8</testng.version>
-    <guava.version>17.0</guava.version>
-    <cxf.version>3.1.4</cxf.version>
+    <surefire.version>2.19.1</surefire.version>
+    <testng.version>6.9.10</testng.version>
+    <guava.version>18.0</guava.version>
+    <cxf.version>3.1.10</cxf.version>
+    <httpcomponents.httpcore.version>4.4.4</httpcomponents.httpcore.version>
+    <httpcomponents.httpasyncclient.version>4.1.2</httpcomponents.httpasyncclient.version>
+    <httpcomponents.httpclient.version>4.5.2</httpcomponents.httpclient.version>
     <mockwebserver.version>3.5.0</mockwebserver.version>
     <xmlunit.version>2.3.0</xmlunit.version>
   </properties>
@@ -130,12 +133,39 @@
           </archive>
         </configuration>
       </plugin>
+      <plugin>
+        <artifactId>maven-enforcer-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>enforce</id>
+            <phase>none</phase>
+          </execution>
+          <execution>
+            <id>brooklyn-build-req</id>
+            <goals>
+              <goal>enforce</goal>
+            </goals>
+            <inherited>true</inherited>
+            <configuration>
+              <rules>
+                <requireJavaVersion>
+                  <version>${java.version}.0</version>
+                </requireJavaVersion>
+                <requireMavenVersion>
+                  <version>[3.0.0,)</version>
+                </requireMavenVersion>
+                <dependencyConvergence/>
+              </rules>
+            </configuration>
+          </execution>
+      </executions>
+    </plugin>
     </plugins>
     <pluginManagement>
       <plugins>
         <plugin>
           <artifactId>maven-compiler-plugin</artifactId>
-          <version>3.3</version>
+          <version>3.6.0</version>
           <configuration>
             <source>${java.version}</source>
             <target>${java.version}</target>
@@ -144,7 +174,7 @@
         <plugin>
           <groupId>org.jvnet.jax-ws-commons</groupId>
           <artifactId>jaxws-maven-plugin</artifactId>
-          <version>2.2</version>
+          <version>2.3</version>
         </plugin>
         <plugin>
           <groupId>org.apache.cxf</groupId>
@@ -159,12 +189,12 @@
         <plugin>
           <groupId>org.codehaus.mojo</groupId>
           <artifactId>build-helper-maven-plugin</artifactId>
-          <version>1.10</version>
+          <version>1.12</version>
         </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-dependency-plugin</artifactId>
-          <version>2.10</version>
+          <version>3.0.0</version>
         </plugin>
         <plugin>
           <artifactId>maven-deploy-plugin</artifactId>
@@ -180,7 +210,7 @@
         </plugin>
         <plugin>
           <artifactId>maven-jar-plugin</artifactId>
-          <version>2.6</version>
+          <version>3.0.2</version>
         </plugin>
         <plugin>
           <groupId>org.apache.felix</groupId>
@@ -189,19 +219,19 @@
         </plugin>
         <plugin>
           <artifactId>maven-resources-plugin</artifactId>
-          <version>2.7</version>
+          <version>3.0.2</version>
         </plugin>
         <plugin>
           <artifactId>maven-source-plugin</artifactId>
-          <version>2.4</version>
+          <version>3.0.1</version>
         </plugin>
         <plugin>
           <artifactId>maven-assembly-plugin</artifactId>
-          <version>2.6</version>
+          <version>3.0.0</version>
         </plugin>
         <plugin>
           <artifactId>maven-clean-plugin</artifactId>
-          <version>2.6.1</version>
+          <version>3.0.0</version>
         </plugin>
         <plugin>
           <artifactId>maven-eclipse-plugin</artifactId>
@@ -213,7 +243,7 @@
         </plugin>
         <plugin>
           <artifactId>maven-javadoc-plugin</artifactId>
-          <version>2.10.3</version>
+          <version>2.10.4</version>
         </plugin>
         <plugin>
           <artifactId>maven-gpg-plugin</artifactId>
@@ -221,7 +251,7 @@
         </plugin>
         <plugin>
           <artifactId>maven-release-plugin</artifactId>
-          <version>2.5.2</version>
+          <version>2.5.3</version>
         </plugin>
         <!--This plugin's configuration is used to store Eclipse m2e settings 
           only. It has no influence on the Maven build itself. -->