diff --git a/core/src/test/java/org/elasticsearch/search/aggregations/AggregatorTestCase.java b/core/src/test/java/org/elasticsearch/search/aggregations/AggregatorTestCase.java
index 296a2ec4611..aa23dfdb7a5 100644
--- a/core/src/test/java/org/elasticsearch/search/aggregations/AggregatorTestCase.java
+++ b/core/src/test/java/org/elasticsearch/search/aggregations/AggregatorTestCase.java
@@ -180,9 +180,9 @@ public abstract class AggregatorTestCase extends ESTestCase {
             if (aggs.isEmpty()) {
                 return null;
             } else {
-                if (aggs.size() > 2 && randomBoolean()) {
+                if (randomBoolean()) {
                     // sometimes do an incremental reduce
-                    List<InternalAggregation> internalAggregations = randomSubsetOf(randomIntBetween(2, aggs.size()-1), aggs);
+                    List<InternalAggregation> internalAggregations = randomSubsetOf(randomIntBetween(1, aggs.size()), aggs);
                     A internalAgg = (A) aggs.get(0).doReduce(internalAggregations,
                         new InternalAggregation.ReduceContext(root.context().bigArrays(), null, false));
                     aggs.removeAll(internalAggregations);
diff --git a/core/src/test/java/org/elasticsearch/search/aggregations/InternalAggregationTestCase.java b/core/src/test/java/org/elasticsearch/search/aggregations/InternalAggregationTestCase.java
index f7d105ac8da..502767e07bf 100644
--- a/core/src/test/java/org/elasticsearch/search/aggregations/InternalAggregationTestCase.java
+++ b/core/src/test/java/org/elasticsearch/search/aggregations/InternalAggregationTestCase.java
@@ -57,8 +57,9 @@ public abstract class InternalAggregationTestCase<T extends InternalAggregation>
             inputs.add(t);
             toReduce.add(t);
         }
-        if (randomBoolean() && toReduceSize >= 2) {
-            List<InternalAggregation> internalAggregations = randomSubsetOf(randomIntBetween(2, toReduceSize - 2), toReduce);
+        if (randomBoolean()) {
+            // we leave at least one in the list
+            List<InternalAggregation> internalAggregations = randomSubsetOf(randomIntBetween(1, toReduceSize), toReduce);
             InternalAggregation.ReduceContext context = new InternalAggregation.ReduceContext(null, null, true);
             @SuppressWarnings("unchecked")
             T reduced = (T) inputs.get(0).reduce(internalAggregations, context);
diff --git a/core/src/test/java/org/elasticsearch/search/aggregations/metrics/InternalExtendedStatsTests.java b/core/src/test/java/org/elasticsearch/search/aggregations/metrics/InternalExtendedStatsTests.java
index 73b1ad914d7..83e1815f398 100644
--- a/core/src/test/java/org/elasticsearch/search/aggregations/metrics/InternalExtendedStatsTests.java
+++ b/core/src/test/java/org/elasticsearch/search/aggregations/metrics/InternalExtendedStatsTests.java
@@ -30,7 +30,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 
-public class InternalExtendedStatsTests  extends InternalAggregationTestCase<InternalExtendedStats> {
+public class InternalExtendedStatsTests extends InternalAggregationTestCase<InternalExtendedStats> {
     private double sigma;
 
     @Before