diff --git a/src/java/com/samskivert/util/Histogram.java b/src/java/com/samskivert/util/Histogram.java
index 70cc7520..73b736ce 100644
--- a/src/java/com/samskivert/util/Histogram.java
+++ b/src/java/com/samskivert/util/Histogram.java
@@ -109,7 +109,7 @@ public class Histogram
             chisto._buckets = _buckets.clone();
             return chisto;
         } catch (CloneNotSupportedException cnse) {
-            throw new AssertionError();
+            throw new AssertionError(cnse);
         }
     }