diff --git a/src/java/com/threerings/stats/data/Stat.java b/src/java/com/threerings/stats/data/Stat.java
index da43330d..e51b52c7 100644
--- a/src/java/com/threerings/stats/data/Stat.java
+++ b/src/java/com/threerings/stats/data/Stat.java
@@ -175,7 +175,7 @@ public abstract class Stat
     @Override
     public String toString ()
     {
-        StringBuffer buf = new StringBuffer(StringUtil.toUSLowerCase(_type.name()));
+        StringBuilder buf = new StringBuilder(StringUtil.toUSLowerCase(_type.name()));
         buf.append("=").append(valueToString());
         buf.append("(").append(_modCount).append(")");
         return buf.toString();
diff --git a/src/java/com/threerings/stats/data/StringMapStat.java b/src/java/com/threerings/stats/data/StringMapStat.java
index 822da43a..04670f25 100644
--- a/src/java/com/threerings/stats/data/StringMapStat.java
+++ b/src/java/com/threerings/stats/data/StringMapStat.java
@@ -93,7 +93,7 @@ public abstract class StringMapStat extends Stat
     @Override
     public String valueToString ()
     {
-        StringBuffer buf = new StringBuffer("[");
+        StringBuilder buf = new StringBuilder("[");
         for (int ii = 0; ii < _keys.length; ii++) {
             if (ii > 0) {
                 buf.append(", ");