diff --git a/src/as/com/threerings/flash/Siner.as b/src/as/com/threerings/flash/Siner.as
index be96b99d..f50da813 100644
--- a/src/as/com/threerings/flash/Siner.as
+++ b/src/as/com/threerings/flash/Siner.as
@@ -4,7 +4,7 @@ import flash.utils.getTimer;
 
 /**
  * Tracks multiple sine waves with different periods and amplitudes, and
- * returns a
+ * returns an instantaneous additive amplitude.
  */
 public class Siner
 {