diff --git a/scripts/base/frameworks/sumstats/non-cluster.bro b/scripts/base/frameworks/sumstats/non-cluster.bro
index 97e1817598..9cf4041fc0 100644
--- a/scripts/base/frameworks/sumstats/non-cluster.bro
+++ b/scripts/base/frameworks/sumstats/non-cluster.bro
@@ -2,23 +2,47 @@
 
 module SumStats;
 
+event SumStats::process_epoch_result(ss: SumStat, now: time, data: ResultTable)
+	{
+	# TODO: is this the right processing group size?
+	local i = 50;
+	for ( key in data )
+		{
+		ss$epoch_result(now, key, data[key]);
+		delete data[key];
+
+		if ( |data| == 0 )
+			{
+			if ( ss?$epoch_finished )
+				ss$epoch_finished(now);
+
+			# Now that no data is left we can finish.
+			return;
+			}
+
+		i = i-1;
+		if ( i == 0 )
+			{
+			# TODO: is this the right interval?
+			schedule 0.01 secs { process_epoch_result(ss, now, data) };
+			break;
+			}
+		}
+	}
+
 event SumStats::finish_epoch(ss: SumStat)
 	{
 	if ( ss$name in result_store )
 		{
-		local now = network_time();
-
 		if ( ss?$epoch_result )
 			{
 			local data = result_store[ss$name];
-			# TODO: don't block here.
-			for ( key in data )
-				ss$epoch_result(now, key, data[key]);
+			event SumStats::process_epoch_result(ss, network_time(), data);
 			}
 
-		if ( ss?$epoch_finished )
-			ss$epoch_finished(now);
-
+		# We can reset here because we know that the reference
+		# to the data will be maintained by the process_epoch_result
+		# event.
 		reset(ss);
 		}
 
diff --git a/testing/btest/Baseline/scripts.base.frameworks.sumstats.basic/.stdout b/testing/btest/Baseline/scripts.base.frameworks.sumstats.basic/standalone..stdout
similarity index 100%
rename from testing/btest/Baseline/scripts.base.frameworks.sumstats.basic/.stdout
rename to testing/btest/Baseline/scripts.base.frameworks.sumstats.basic/standalone..stdout
diff --git a/testing/btest/scripts/base/frameworks/sumstats/basic.bro b/testing/btest/scripts/base/frameworks/sumstats/basic.bro
index fb1254baca..6b153dfe39 100644
--- a/testing/btest/scripts/base/frameworks/sumstats/basic.bro
+++ b/testing/btest/scripts/base/frameworks/sumstats/basic.bro
@@ -1,5 +1,8 @@
-# @TEST-EXEC: bro %INPUT
-# @TEST-EXEC: btest-diff .stdout
+# @TEST-EXEC: btest-bg-run standalone bro %INPUT
+# @TEST-EXEC: btest-bg-wait 5
+# @TEST-EXEC: btest-diff standalone/.stdout
+
+redef exit_only_after_terminate=T;
 
 event bro_init() &priority=5
 	{
@@ -19,8 +22,9 @@ event bro_init() &priority=5
 	                  	{
 	                  	local r = result["test.metric"];
 	                  	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$unique, r$hll_unique);
+	                  	terminate();
 	                  	}
-		 ]);
+	                 ])
 
 	SumStats::observe("test.metric", [$host=1.2.3.4], [$num=5]);
 	SumStats::observe("test.metric", [$host=1.2.3.4], [$num=22]);