diff --git a/src/as/com/threerings/io/ObjectInputStream.as b/src/as/com/threerings/io/ObjectInputStream.as
index 8d910a108..209b5692e 100644
--- a/src/as/com/threerings/io/ObjectInputStream.as
+++ b/src/as/com/threerings/io/ObjectInputStream.as
@@ -202,11 +202,12 @@ public class ObjectInputStream
      * Read bytes into the byte array. If length is not specified, then
      * enough bytes to fill the array (from the offset) are read.
      */
-    public function readBytes (bytes :ByteArray, offset :int = 0, length :int = -1) :void
+    public function readBytes (
+        bytes :ByteArray, offset :uint = 0, length :uint = uint.MAX_VALUE) :void
         //throws IOError
     {
         // if no length specified then fill the ByteArray
-        if (length == -1) {
+        if (length == uint.MAX_VALUE) {
             length = bytes.length - offset;
         }
         // And, if we really want to read 0 bytes then just don't do anything, because an
diff --git a/src/as/com/threerings/io/ObjectOutputStream.as b/src/as/com/threerings/io/ObjectOutputStream.as
index 0901c01b7..a43255cf2 100644
--- a/src/as/com/threerings/io/ObjectOutputStream.as
+++ b/src/as/com/threerings/io/ObjectOutputStream.as
@@ -164,10 +164,11 @@ public class ObjectOutputStream
         _targ.writeByte(value);
     }
 
-    public function writeBytes (bytes :ByteArray, offset :int = 0, length :int = -1) :void
+    public function writeBytes (
+        bytes :ByteArray, offset :uint = 0, length :uint = uint.MAX_VALUE) :void
         //throws IOError
     {
-        if (length == -1) {
+        if (length == uint.MAX_VALUE) {
             length = bytes.length - offset;
         }
         if (length > 0) {