diff --git a/hbase-common/src/main/java/org/apache/hadoop/hbase/CompoundConfiguration.java b/hbase-common/src/main/java/org/apache/hadoop/hbase/CompoundConfiguration.java
index 53ba89ece06..b597fe6ca12 100644
--- a/hbase-common/src/main/java/org/apache/hadoop/hbase/CompoundConfiguration.java
+++ b/hbase-common/src/main/java/org/apache/hadoop/hbase/CompoundConfiguration.java
@@ -261,7 +261,7 @@ public class CompoundConfiguration extends Configuration {
 
   @Override
   public String toString() {
-    StringBuffer sb = new StringBuffer();
+    StringBuilder sb = new StringBuilder();
     sb.append("CompoundConfiguration: " + this.configs.size() + " configs");
     for (ImmutableConfigMap m : this.configs) {
       sb.append(m);
diff --git a/hbase-common/src/main/java/org/apache/hadoop/hbase/rsgroup/RSGroupInfo.java b/hbase-common/src/main/java/org/apache/hadoop/hbase/rsgroup/RSGroupInfo.java
index d3ccd3fff75..5408083e42f 100644
--- a/hbase-common/src/main/java/org/apache/hadoop/hbase/rsgroup/RSGroupInfo.java
+++ b/hbase-common/src/main/java/org/apache/hadoop/hbase/rsgroup/RSGroupInfo.java
@@ -124,7 +124,7 @@ public class RSGroupInfo {
 
   @Override
   public String toString() {
-    StringBuffer sb = new StringBuffer();
+    StringBuilder sb = new StringBuilder();
     sb.append("Name:");
     sb.append(this.name);
     sb.append(", ");