diff --git a/src/as/com/threerings/cast/MultiFrameBitmap.as b/src/as/com/threerings/cast/MultiFrameBitmap.as
index 7146d27b..c64e3a82 100644
--- a/src/as/com/threerings/cast/MultiFrameBitmap.as
+++ b/src/as/com/threerings/cast/MultiFrameBitmap.as
@@ -49,12 +49,7 @@ public class MultiFrameBitmap extends Sprite
         }
 
         var elapsedTime :int = (tickStamp - _start);
-        var frameIndex :int = Math.floor(elapsedTime * _frameRate);
-        var totalFrames :int = _frames.length;
-        if (frameIndex >= totalFrames) {
-            frameIndex = frameIndex % totalFrames;
-        }
-
+        var frameIndex :int = Math.floor(elapsedTime * _frameRate) % _frames.length;
         setFrame(frameIndex);
     }
 
@@ -108,4 +103,4 @@ public class MultiFrameBitmap extends Sprite
 
     protected var _curFrameIndex :int = -1;
 }
-}
\ No newline at end of file
+}