diff --git a/common/util/src/main/java/io/apiman/common/util/SimpleStringUtils.java b/common/util/src/main/java/io/apiman/common/util/SimpleStringUtils.java
index fbea66b697..39df23ccc7 100644
--- a/common/util/src/main/java/io/apiman/common/util/SimpleStringUtils.java
+++ b/common/util/src/main/java/io/apiman/common/util/SimpleStringUtils.java
@@ -43,14 +43,14 @@ public static String trim(String string) {
      * Join together varargs using a join sequence.
      * <p>
      * <tt>join("-", a, b, c) => a-b-c</tt>
-     * 
+     *
      * @param joinChar character to join string
      * @param args strings to join
      * @return joined string
      */
     public static String join(String joinChar, String... args) {
         String next = ""; //$NON-NLS-1$
-        StringBuffer result = new StringBuffer(length(args) + (args.length - 1));
+        StringBuilder result = new StringBuilder(length(args) + (args.length - 1));
 
         for (String arg : args) {
             result.append(next);
diff --git a/gateway/platforms/servlet/src/test/java/io/apiman/gateway/platforms/servlet/auth/tls/CipherAndProtocolSelectionTest.java b/gateway/platforms/servlet/src/test/java/io/apiman/gateway/platforms/servlet/auth/tls/CipherAndProtocolSelectionTest.java
index d1003a9db6..5e7b111ec2 100644
--- a/gateway/platforms/servlet/src/test/java/io/apiman/gateway/platforms/servlet/auth/tls/CipherAndProtocolSelectionTest.java
+++ b/gateway/platforms/servlet/src/test/java/io/apiman/gateway/platforms/servlet/auth/tls/CipherAndProtocolSelectionTest.java
@@ -378,7 +378,7 @@ private String getPrefferedCipher() throws Exception {
 
         server.start();
 
-        final StringBuffer sbuff = new StringBuffer();
+        final StringBuilder sbuff = new StringBuilder();
         final CountDownLatch latch = new CountDownLatch(1);
 
         HttpConnectorFactory factory = new HttpConnectorFactory(config);
diff --git a/test/common/src/main/java/io/apiman/test/common/mock/EchoServlet.java b/test/common/src/main/java/io/apiman/test/common/mock/EchoServlet.java
index 707ebaef89..b5c348cdb5 100644
--- a/test/common/src/main/java/io/apiman/test/common/mock/EchoServlet.java
+++ b/test/common/src/main/java/io/apiman/test/common/mock/EchoServlet.java
@@ -108,7 +108,7 @@ public static EchoResponse response(HttpServletRequest request, boolean withBody
                 };
 
                 byte[] hashBytes = sha1.digest();
-                StringBuffer sb = new StringBuffer();
+                StringBuilder sb = new StringBuilder();
                 for (int i = 0; i < hashBytes.length; i++) {
                   sb.append(Integer.toString((hashBytes[i] & 0xff) + 0x100, 16).substring(1));
                 }
@@ -130,7 +130,7 @@ public static EchoResponse response(HttpServletRequest request, boolean withBody
      */
     public EchoServlet() {
     }
-    
+
     /**
      * @see javax.servlet.http.HttpServlet#service(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
      */