diff --git a/velox/functions/prestosql/aggregates/ApproxPercentileAggregate.cpp b/velox/functions/prestosql/aggregates/ApproxPercentileAggregate.cpp
index 4a5b0354b035..4e3754536bca 100644
--- a/velox/functions/prestosql/aggregates/ApproxPercentileAggregate.cpp
+++ b/velox/functions/prestosql/aggregates/ApproxPercentileAggregate.cpp
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+#include "velox/functions/prestosql/aggregates/ApproxPercentileAggregate.h"
 #include "velox/common/base/IOUtils.h"
 #include "velox/common/base/Macros.h"
 #include "velox/common/base/RandomUtil.h"
@@ -169,18 +170,6 @@ struct KllSketchAccumulator {
       largeCountValues_;
 };
 
-enum IntermediateTypeChildIndex {
-  kPercentiles = 0,
-  kPercentilesIsArray = 1,
-  kAccuracy = 2,
-  kK = 3,
-  kN = 4,
-  kMinValue = 5,
-  kMaxValue = 6,
-  kItems = 7,
-  kLevels = 8,
-};
-
 void checkWeight(int64_t weight) {
   constexpr int64_t kMaxWeight = (1ll << 60) - 1;
   VELOX_USER_CHECK(
diff --git a/velox/functions/prestosql/aggregates/ApproxPercentileAggregate.h b/velox/functions/prestosql/aggregates/ApproxPercentileAggregate.h
new file mode 100644
index 000000000000..3981611dc04d
--- /dev/null
+++ b/velox/functions/prestosql/aggregates/ApproxPercentileAggregate.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+namespace facebook::velox::aggregate::prestosql {
+
+enum ApproxPercentileIntermediateTypeChildIndex {
+  kPercentiles = 0,
+  kPercentilesIsArray = 1,
+  kAccuracy = 2,
+  kK = 3,
+  kN = 4,
+  kMinValue = 5,
+  kMaxValue = 6,
+  kItems = 7,
+  kLevels = 8,
+};
+
+} // namespace facebook::velox::aggregate::prestosql