diff --git a/muted-tests.yml b/muted-tests.yml
index b5cadd72fa12f..b4f2035d62709 100644
--- a/muted-tests.yml
+++ b/muted-tests.yml
@@ -420,9 +420,6 @@ tests:
 - class: org.elasticsearch.xpack.security.authc.jwt.JwtRealmAuthenticateTests
   method: testJwkUpdatesByReloadWithFile
   issue: https://github.com/elastic/elasticsearch/issues/138397
-- class: org.elasticsearch.compute.data.ExponentialHistogramBlockTests
-  method: testComponentAccess
-  issue: https://github.com/elastic/elasticsearch/issues/138399
 
 # Examples:
 #
diff --git a/x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/mapper/ExponentialHistogramParserTests.java b/x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/mapper/ExponentialHistogramParserTests.java
index 3c48e06c71760..664cce981f049 100644
--- a/x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/mapper/ExponentialHistogramParserTests.java
+++ b/x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/mapper/ExponentialHistogramParserTests.java
@@ -35,29 +35,31 @@ public class ExponentialHistogramParserTests extends ESTestCase {
     private static final String TEST_FIELD_NAME = "test_field";
 
     public void testParseRandomHistogram() throws IOException {
-        ExponentialHistogram histogram = ExponentialHistogramTestUtils.randomHistogram();
+        for (int i = 0; i < 20; i++) {
+            ExponentialHistogram histogram = ExponentialHistogramTestUtils.randomHistogram();
 
-        ExponentialHistogramParser.ParsedExponentialHistogram parsed;
-        try (XContentBuilder builder = XContentFactory.jsonBuilder()) {
-            ExponentialHistogramXContent.serialize(builder, histogram);
-            String json = Strings.toString(builder);
-            parsed = doParse(json);
-        }
+            ExponentialHistogramParser.ParsedExponentialHistogram parsed;
+            try (XContentBuilder builder = XContentFactory.jsonBuilder()) {
+                ExponentialHistogramXContent.serialize(builder, histogram);
+                String json = Strings.toString(builder);
+                parsed = doParse(json);
+            }
 
-        List<IndexWithCount> expectedPositiveBuckets = IndexWithCount.fromIterator(histogram.positiveBuckets().iterator());
-        List<IndexWithCount> expectedNegativeBuckets = IndexWithCount.fromIterator(histogram.negativeBuckets().iterator());
+            List<IndexWithCount> expectedPositiveBuckets = IndexWithCount.fromIterator(histogram.positiveBuckets().iterator());
+            List<IndexWithCount> expectedNegativeBuckets = IndexWithCount.fromIterator(histogram.negativeBuckets().iterator());
 
-        assertThat(parsed.scale(), equalTo(histogram.scale()));
+            assertThat(parsed.scale(), equalTo(histogram.scale()));
 
-        assertThat(parsed.zeroThreshold(), equalTo(histogram.zeroBucket().zeroThreshold()));
-        assertThat(parsed.zeroCount(), equalTo(histogram.zeroBucket().count()));
+            assertThat(parsed.zeroThreshold(), equalTo(histogram.zeroBucket().zeroThreshold()));
+            assertThat(parsed.zeroCount(), equalTo(histogram.zeroBucket().count()));
 
-        assertThat(parsed.positiveBuckets(), equalTo(expectedPositiveBuckets));
-        assertThat(parsed.negativeBuckets(), equalTo(expectedNegativeBuckets));
+            assertThat(parsed.positiveBuckets(), equalTo(expectedPositiveBuckets));
+            assertThat(parsed.negativeBuckets(), equalTo(expectedNegativeBuckets));
 
-        assertThat(parsed.sum(), equalTo(histogram.sum()));
-        assertThat(parsed.min(), equalTo(Double.isNaN(histogram.min()) ? null : histogram.min()));
-        assertThat(parsed.max(), equalTo(Double.isNaN(histogram.max()) ? null : histogram.max()));
+            assertThat(parsed.sum(), equalTo(histogram.valueCount() == 0 ? null : histogram.sum()));
+            assertThat(parsed.min(), equalTo(Double.isNaN(histogram.min()) ? null : histogram.min()));
+            assertThat(parsed.max(), equalTo(Double.isNaN(histogram.max()) ? null : histogram.max()));
+        }
     }
 
     public void testParseScaleMissing() {
diff --git a/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/data/ExponentialHistogramBlockTests.java b/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/data/ExponentialHistogramBlockTests.java
index 9b9c96bce33df..4136d7a1b7900 100644
--- a/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/data/ExponentialHistogramBlockTests.java
+++ b/x-pack/plugin/esql/compute/src/test/java/org/elasticsearch/compute/data/ExponentialHistogramBlockTests.java
@@ -95,9 +95,13 @@ public void testComponentAccess() {
                             }
                         }
                         case SUM -> {
-                            assertThat(componentBlock.getValueCount(i), equalTo(1));
-                            int valueIndex = componentBlock.getFirstValueIndex(i);
-                            assertThat(((DoubleBlock) componentBlock).getDouble(valueIndex), equalTo(histo.sum()));
+                            if (histo.valueCount() == 0) {
+                                assertThat(componentBlock.isNull(i), equalTo(true));
+                            } else {
+                                assertThat(componentBlock.getValueCount(i), equalTo(1));
+                                int valueIndex = componentBlock.getFirstValueIndex(i);
+                                assertThat(((DoubleBlock) componentBlock).getDouble(valueIndex), equalTo(histo.sum()));
+                            }
                         }
                         case COUNT -> {
                             assertThat(componentBlock.getValueCount(i), equalTo(1));