diff --git a/velox/functions/lib/RegistrationHelpers.h b/velox/functions/lib/RegistrationHelpers.h
index e411057d8cd29..cea30c50a2a1e 100644
--- a/velox/functions/lib/RegistrationHelpers.h
+++ b/velox/functions/lib/RegistrationHelpers.h
@@ -73,6 +73,14 @@ void registerUnaryIntegral(const std::vector<std::string>& aliases) {
   registerFunction<T, int64_t, int64_t>(aliases);
 }
 
+template <template <class> class T, typename TReturn>
+void registerUnaryIntegralWithTReturn(const std::vector<std::string>& aliases) {
+  registerFunction<T, TReturn, int8_t>(aliases);
+  registerFunction<T, TReturn, int16_t>(aliases);
+  registerFunction<T, TReturn, int32_t>(aliases);
+  registerFunction<T, TReturn, int64_t>(aliases);
+}
+
 template <template <class> class T>
 void registerUnaryFloatingPoint(const std::vector<std::string>& aliases) {
   registerFunction<T, double, double>(aliases);
diff --git a/velox/functions/sparksql/Register.cpp b/velox/functions/sparksql/Register.cpp
index 09c38cda9f629..65161a080f027 100644
--- a/velox/functions/sparksql/Register.cpp
+++ b/velox/functions/sparksql/Register.cpp
@@ -148,15 +148,6 @@ inline void registerArrayMinMaxFunctions(const std::string& prefix) {
   registerArrayMinMaxFunctions<Timestamp>(prefix);
   registerArrayMinMaxFunctions<Date>(prefix);
 }
-
-template <template <class> typename T>
-inline void registerIntegralToTimestamp(
-    const std::vector<std::string>& aliases) {
-  registerFunction<T, Timestamp, int8_t>(aliases);
-  registerFunction<T, Timestamp, int16_t>(aliases);
-  registerFunction<T, Timestamp, int32_t>(aliases);
-  registerFunction<T, Timestamp, int64_t>(aliases);
-}
 } // namespace
 
 void registerFunctions(const std::string& prefix) {
@@ -399,11 +390,11 @@ void registerFunctions(const std::string& prefix) {
 
   registerFunction<TimestampToMicrosFunction, int64_t, Timestamp>(
       {prefix + "unix_micros"});
-  registerIntegralToTimestamp<MicrosToTimestampFunction>(
+  registerUnaryIntegralWithTReturn<MicrosToTimestampFunction, Timestamp>(
       {prefix + "timestamp_micros"});
   registerFunction<TimestampToMillisFunction, int64_t, Timestamp>(
       {prefix + "unix_millis"});
-  registerIntegralToTimestamp<MillisToTimestampFunction>(
+  registerUnaryIntegralWithTReturn<MillisToTimestampFunction, Timestamp>(
       {prefix + "timestamp_millis"});
 
   // Register bloom filter function