diff --git a/src/main/kotlin/org/opensearch/indexmanagement/rollup/util/RollupUtils.kt b/src/main/kotlin/org/opensearch/indexmanagement/rollup/util/RollupUtils.kt
index 2bbfd6092..988fa9643 100644
--- a/src/main/kotlin/org/opensearch/indexmanagement/rollup/util/RollupUtils.kt
+++ b/src/main/kotlin/org/opensearch/indexmanagement/rollup/util/RollupUtils.kt
@@ -214,7 +214,7 @@ fun Rollup.rewriteAggregationBuilder(aggregationBuilder: AggregationBuilder): Ag
         }
         is AvgAggregationBuilder -> {
             ScriptedMetricAggregationBuilder(aggregationBuilder.name)
-                .initScript(Script(ScriptType.INLINE, Script.DEFAULT_SCRIPT_LANG, "state.sums = 0; state.counts = 0;", emptyMap()))
+                .initScript(Script(ScriptType.INLINE, Script.DEFAULT_SCRIPT_LANG, "state.sums = 0D; state.counts = 0L;", emptyMap()))
                 .mapScript(
                     Script(
                         ScriptType.INLINE, Script.DEFAULT_SCRIPT_LANG,
@@ -227,7 +227,7 @@ fun Rollup.rewriteAggregationBuilder(aggregationBuilder: AggregationBuilder): Ag
                 .combineScript(
                     Script(
                         ScriptType.INLINE, Script.DEFAULT_SCRIPT_LANG,
-                        "def d = new long[2]; d[0] = state.sums; d[1] = state.counts; return d", emptyMap()
+                        "def d = new double[2]; d[0] = state.sums; d[1] = state.counts; return d", emptyMap()
                     )
                 )
                 .reduceScript(
diff --git a/src/test/kotlin/org/opensearch/indexmanagement/rollup/runner/RollupRunnerIT.kt b/src/test/kotlin/org/opensearch/indexmanagement/rollup/runner/RollupRunnerIT.kt
index 87997e3a0..60898e7bb 100644
--- a/src/test/kotlin/org/opensearch/indexmanagement/rollup/runner/RollupRunnerIT.kt
+++ b/src/test/kotlin/org/opensearch/indexmanagement/rollup/runner/RollupRunnerIT.kt
@@ -25,6 +25,7 @@ import org.opensearch.indexmanagement.rollup.randomRollup
 import org.opensearch.indexmanagement.rollup.settings.RollupSettings.Companion.ROLLUP_SEARCH_BACKOFF_COUNT
 import org.opensearch.indexmanagement.waitFor
 import org.opensearch.jobscheduler.spi.schedule.IntervalSchedule
+import org.opensearch.rest.RestRequest
 import org.opensearch.rest.RestStatus
 import java.time.Instant
 import java.time.temporal.ChronoUnit
@@ -67,6 +68,75 @@ class RollupRunnerIT : RollupRestTestCase() {
         }
     }
 
+    fun `test rollup with avg metric`() {
+        val sourceIdxTestName = "source_idx_test"
+        val targetIdxTestName = "target_idx_test"
+        val propertyName = "passenger_count"
+        val avgMetricName = "avg_passenger_count"
+
+        generateNYCTaxiData(sourceIdxTestName)
+
+        val rollup = Rollup(
+            id = "rollup_test",
+            schemaVersion = 1L,
+            enabled = true,
+            jobSchedule = IntervalSchedule(Instant.now(), 1, ChronoUnit.MINUTES),
+            jobLastUpdatedTime = Instant.now(),
+            jobEnabledTime = Instant.now(),
+            description = "basic stats test",
+            sourceIndex = sourceIdxTestName,
+            targetIndex = targetIdxTestName,
+            metadataID = null,
+            roles = emptyList(),
+            pageSize = 100,
+            delay = 0,
+            continuous = false,
+            dimensions = listOf(DateHistogram(sourceField = "tpep_pickup_datetime", fixedInterval = "1h")),
+            metrics = listOf(
+                RollupMetrics(sourceField = propertyName, targetField = propertyName, metrics = listOf(Average()))
+            )
+        ).let { createRollup(it, it.id) }
+
+        updateRollupStartTime(rollup)
+
+        waitFor { assertTrue("Target rollup index was not created", indexExists(rollup.targetIndex)) }
+
+        waitFor {
+            val rollupJob = getRollup(rollupId = rollup.id)
+            assertNotNull("Rollup job doesn't have metadata set", rollupJob.metadataID)
+            val rollupMetadata = getRollupMetadata(rollupJob.metadataID!!)
+            assertEquals("Rollup is not finished", RollupMetadata.Status.FINISHED, rollupMetadata.status)
+
+            // Term query
+            var req = """
+            {
+                "size": 0,
+                "query": {
+                  "match_all": {}
+                },
+                "aggs": {
+                    "$avgMetricName": {
+                        "avg": {
+                            "field": "$propertyName"
+                        }
+                    }
+                }
+            }
+            """.trimIndent()
+            var rawRes = client().makeRequest(RestRequest.Method.POST.name, "/$sourceIdxTestName/_search", emptyMap(), StringEntity(req, ContentType.APPLICATION_JSON))
+            assertTrue(rawRes.restStatus() == RestStatus.OK)
+            var rollupRes = client().makeRequest(RestRequest.Method.POST.name, "/$targetIdxTestName/_search", emptyMap(), StringEntity(req, ContentType.APPLICATION_JSON))
+            assertTrue(rollupRes.restStatus() == RestStatus.OK)
+            var rawAggRes = rawRes.asMap()["aggregations"] as Map<String, Map<String, Any>>
+            var rollupAggRes = rollupRes.asMap()["aggregations"] as Map<String, Map<String, Any>>
+            assertEquals(
+                "Source and rollup index did not return same avg results",
+                rawAggRes.getValue(avgMetricName)["value"],
+                rollupAggRes.getValue(avgMetricName)["value"]
+            )
+        }
+    }
+
     fun `test metadata is created for data stream rollup job when none exists`() {
         val dataStreamName = "test-data-stream"