diff --git a/pinot-core/src/main/java/org/apache/pinot/core/query/aggregation/function/CountAggregationFunction.java b/pinot-core/src/main/java/org/apache/pinot/core/query/aggregation/function/CountAggregationFunction.java
index 7285ba0b5c71..8bbdda5fcec2 100644
--- a/pinot-core/src/main/java/org/apache/pinot/core/query/aggregation/function/CountAggregationFunction.java
+++ b/pinot-core/src/main/java/org/apache/pinot/core/query/aggregation/function/CountAggregationFunction.java
@@ -21,6 +21,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import javax.annotation.Nullable;
 import org.apache.pinot.common.request.context.ExpressionContext;
 import org.apache.pinot.common.utils.DataSchema.ColumnDataType;
 import org.apache.pinot.core.common.BlockValSet;
@@ -204,8 +205,8 @@ public ColumnDataType getFinalResultColumnType() {
   }
 
   @Override
-  public Long extractFinalResult(Long intermediateResult) {
-    return intermediateResult;
+  public Long extractFinalResult(@Nullable Long intermediateResult) {
+    return intermediateResult != null ? intermediateResult : 0L;
   }
 
   @Override
diff --git a/pinot-core/src/test/java/org/apache/pinot/core/query/aggregation/function/CountAggregationFunctionTest.java b/pinot-core/src/test/java/org/apache/pinot/core/query/aggregation/function/CountAggregationFunctionTest.java
index 360233b0a204..cffce5dce688 100644
--- a/pinot-core/src/test/java/org/apache/pinot/core/query/aggregation/function/CountAggregationFunctionTest.java
+++ b/pinot-core/src/test/java/org/apache/pinot/core/query/aggregation/function/CountAggregationFunctionTest.java
@@ -19,12 +19,16 @@
 
 package org.apache.pinot.core.query.aggregation.function;
 
+import java.util.List;
+import org.apache.pinot.common.request.context.ExpressionContext;
 import org.apache.pinot.queries.FluentQueryTest;
 import org.apache.pinot.spi.data.FieldSpec;
 import org.apache.pinot.spi.data.Schema;
 import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
 
+import static org.testng.Assert.assertEquals;
+
 
 public class CountAggregationFunctionTest extends AbstractAggregationFunctionTest {
 
@@ -234,6 +238,14 @@ public void countGroupByMV() {
         );
   }
 
+  @Test
+  public void testExtractFinalResultReturnsZeroForNull() {
+    CountAggregationFunction function =
+        new CountAggregationFunction(List.of(ExpressionContext.forIdentifier("col")), false);
+    assertEquals(function.extractFinalResult(null), Long.valueOf(0L));
+    assertEquals(function.extractFinalResult(5L), Long.valueOf(5L));
+  }
+
   @DataProvider(name = "nullHandlingEnabled")
   public Object[][] nullHandlingEnabled() {
     return new Object[][]{