diff --git a/core/src/main/java/com/yahoo/ycsb/ByteIterator.java b/core/src/main/java/com/yahoo/ycsb/ByteIterator.java
index 9bb3b63e36fcb6a95dbad08da0ea02cbf43f4005..568cdc1d69f4e4ea53b1fc24aea0071de580a9e6 100644
--- a/core/src/main/java/com/yahoo/ycsb/ByteIterator.java
+++ b/core/src/main/java/com/yahoo/ycsb/ByteIterator.java
@@ -16,8 +16,10 @@
  */
 package com.yahoo.ycsb;
 
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.Charset;
 import java.util.Iterator;
-import java.util.ArrayList;
 /**
  * YCSB-specific buffer class.  ByteIterators are designed to support
  * efficient field generation, and to allow backend drivers that can stream
@@ -73,10 +75,11 @@ public abstract class ByteIterator implements Iterator<Byte> {
 
 	/** Consumes remaining contents of this object, and returns them as a string. */
 	public String toString() {
-		StringBuilder sb = new StringBuilder();
-		while(this.hasNext()) { sb.append((char)nextByte()); }
-		return sb.toString();
+		Charset cset = Charset.forName("UTF-8");
+		CharBuffer cb = cset.decode(ByteBuffer.wrap(this.toArray()));
+		return cb.toString();
 	}
+
 	/** Consumes remaining contents of this object, and returns them as a byte array. */
 	public byte[] toArray() {
 	    long left = bytesLeft();
diff --git a/core/src/main/java/com/yahoo/ycsb/RandomByteIterator.java b/core/src/main/java/com/yahoo/ycsb/RandomByteIterator.java
index 65db4335035ef22be38f249cc9b6ab7dcb92fe7e..cb0977aa56c8f52f4686d84aaaa23f4f30f160c2 100644
--- a/core/src/main/java/com/yahoo/ycsb/RandomByteIterator.java
+++ b/core/src/main/java/com/yahoo/ycsb/RandomByteIterator.java
@@ -34,11 +34,11 @@ public class RandomByteIterator extends ByteIterator {
     int bytes = Utils.random().nextInt();
     try {
       buffer[base+0] = (byte)(((bytes) & 31) + ' ');
-      buffer[base+1] = (byte)(((bytes >> 5) & 31) + ' ');
-      buffer[base+2] = (byte)(((bytes >> 10) & 31) + ' ');
+      buffer[base+1] = (byte)(((bytes >> 5) & 63) + ' ');
+      buffer[base+2] = (byte)(((bytes >> 10) & 95) + ' ');
       buffer[base+3] = (byte)(((bytes >> 15) & 31) + ' ');
-      buffer[base+4] = (byte)(((bytes >> 20) & 31) + ' ');
-      buffer[base+5] = (byte)(((bytes >> 25) & 31) + ' ');
+      buffer[base+4] = (byte)(((bytes >> 20) & 63) + ' ');
+      buffer[base+5] = (byte)(((bytes >> 25) & 95) + ' ');
     } catch (ArrayIndexOutOfBoundsException e) { /* ignore it */ }
   }