diff --git a/scripts/base/frameworks/measurement/plugins/hll_unique.bro b/scripts/base/frameworks/measurement/plugins/hll_unique.bro
index 0e95e6fcdd..ccdb872606 100644
--- a/scripts/base/frameworks/measurement/plugins/hll_unique.bro
+++ b/scripts/base/frameworks/measurement/plugins/hll_unique.bro
@@ -10,14 +10,23 @@ export {
 	redef record ResultVal += {
 		## If cardinality is being tracked, the number of unique
 		## items is tracked here.
-		hllunique: opaque of cardinality &default=hll_cardinality_init(0.01);
+		hllunique: count &default=0;
 	};
 }
 
+redef record ResultVal += {
+	# Internal use only.  This is not meant to be publically available 
+	# because probabilistic data structures have to be examined using
+	# specialized bifs.
+	card: opaque of cardinality &default=hll_cardinality_init(0.01);
+};
+
+
 hook init_resultval_hook(r: Reducer, rv: ResultVal)
 	{
-	if ( HLLUNIQUE in r$apply && ! rv?$hllunique )
-		rv$hllunique = hll_cardinality_init(0.01);
+	if ( HLLUNIQUE in r$apply && ! rv?$card )
+		rv$card = hll_cardinality_init(0.01);
+		rv$hllunique = 0;
 	}
 
 
@@ -25,15 +34,17 @@ hook add_to_reducer_hook(r: Reducer, val: double, data: DataPoint, rv: ResultVal
 	{
 	if ( HLLUNIQUE in r$apply )
 		{
-		hll_cardinality_add(rv$hllunique, data);
+		hll_cardinality_add(rv$card, data);
+		rv$hllunique = double_to_count(hll_cardinality_estimate(rv$card));
 		}
 	}
 
 hook compose_resultvals_hook(result: ResultVal, rv1: ResultVal, rv2: ResultVal)
 	{
 	local rhll = hll_cardinality_init(0.01);
-	hll_cardinality_merge_into(rhll, rv1$hllunique);
-	hll_cardinality_merge_into(rhll, rv2$hllunique);
+	hll_cardinality_merge_into(rhll, rv1$card);
+	hll_cardinality_merge_into(rhll, rv2$card);
 
-	result$hllunique = rhll;
+	result$card = rhll;
+	result$hllunique = double_to_count(hll_cardinality_estimate(rhll));
 	}
diff --git a/testing/btest/scripts/base/frameworks/measurement/basic.bro b/testing/btest/scripts/base/frameworks/measurement/basic.bro
index 4706a7c9b1..701b79fbb3 100644
--- a/testing/btest/scripts/base/frameworks/measurement/basic.bro
+++ b/testing/btest/scripts/base/frameworks/measurement/basic.bro
@@ -19,7 +19,7 @@ event bro_init() &priority=5
 	                     	for ( key in data )
 	                     		{
 	                     		local r = data[key]["test.metric"];
-	                     		print fmt("Host: %s - num:%d - sum:%.1f - var:%.1f - avg:%.1f - max:%.1f - min:%.1f - std_dev:%.1f - unique:%d - hllunique:%.1f", key$host, r$num, r$sum, r$variance, r$average, r$max, r$min, r$std_dev, r$unique, hll_cardinality_estimate(r$hllunique));
+	                     		print fmt("Host: %s - num:%d - sum:%.1f - var:%.1f - avg:%.1f - max:%.1f - min:%.1f - std_dev:%.1f - unique:%d - hllunique:%d", key$host, r$num, r$sum, r$variance, r$average, r$max, r$min, r$std_dev, r$unique, r$hllunique);
 	                     		}
 	                     	}
 		 ]);