diff --git a/javasrc/org/hd/d/statsHouse/feedHits/data/FeedStatus.java b/javasrc/org/hd/d/statsHouse/feedHits/data/FeedStatus.java
index 4c4fdba..14842d8 100644
--- a/javasrc/org/hd/d/statsHouse/feedHits/data/FeedStatus.java
+++ b/javasrc/org/hd/d/statsHouse/feedHits/data/FeedStatus.java
@@ -42,6 +42,8 @@
  * <p>
  * All integer values are non-negative, all Strings are non-null, cols is non-null.
  * <p>
+ * The colTypes element count must match cols.
+ * <p>
  * This makes an immutable copy of the cols data to ensure record immutability.
  */
 public record FeedStatus(int hits, int bytes, String colTypes, List<Integer> cols, String index)
@@ -52,6 +54,7 @@ public record FeedStatus(int hits, int bytes, String colTypes, List<Integer> col
 		if(bytes < 0) { throw new IllegalArgumentException(); }
 		Objects.nonNull(colTypes);
 		Objects.nonNull(cols);
+		for(final int c : cols) { if(c < 0) { throw new IllegalArgumentException(); } }
 		Objects.nonNull(index);
 		if(cols.size() != colTypes.split(":").length) { throw new IllegalArgumentException("colTypes element count must match cols"); }
 	    }