diff --git a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/functions/BuiltinFunctions.java b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/functions/BuiltinFunctions.java
index 0c9f0dd..56971eb 100644
--- a/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/functions/BuiltinFunctions.java
+++ b/asterixdb/asterix-om/src/main/java/org/apache/asterix/om/functions/BuiltinFunctions.java
@@ -1799,28 +1799,26 @@
         addPrivateFunction(MAKE_FIELD_NAME_HANDLE, AnyTypeComputer.INSTANCE, true);
 
         // cast null type constructors
-        addPrivateFunction(BOOLEAN_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_BOOLEAN, true);
-        addPrivateFunction(INT8_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_INT8, true);
-        addPrivateFunction(INT16_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_INT16, true);
-        addPrivateFunction(INT32_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_INT32, true);
-        addPrivateFunction(INT64_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_INT64, true);
-        addPrivateFunction(FLOAT_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_FLOAT, true);
-        addPrivateFunction(DOUBLE_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_DOUBLE, true);
-        addPrivateFunction(STRING_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_STRING, true);
-        addPrivateFunction(DATE_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_DATE, true);
-        addPrivateFunction(DATE_DEFAULT_NULL_CONSTRUCTOR_WITH_FORMAT, NullableTypeComputer.INSTANCE_DATE, true);
-        addPrivateFunction(TIME_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_TIME, true);
-        addPrivateFunction(TIME_DEFAULT_NULL_CONSTRUCTOR_WITH_FORMAT, NullableTypeComputer.INSTANCE_TIME, true);
-        addPrivateFunction(DATETIME_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_DATE_TIME, true);
-        addPrivateFunction(DATETIME_DEFAULT_NULL_CONSTRUCTOR_WITH_FORMAT, NullableTypeComputer.INSTANCE_DATE_TIME,
+        addFunction(BOOLEAN_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_BOOLEAN, true);
+        addFunction(INT8_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_INT8, true);
+        addFunction(INT16_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_INT16, true);
+        addFunction(INT32_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_INT32, true);
+        addFunction(INT64_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_INT64, true);
+        addFunction(FLOAT_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_FLOAT, true);
+        addFunction(DOUBLE_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_DOUBLE, true);
+        addFunction(STRING_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_STRING, true);
+        addFunction(DATE_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_DATE, true);
+        addFunction(DATE_DEFAULT_NULL_CONSTRUCTOR_WITH_FORMAT, NullableTypeComputer.INSTANCE_DATE, true);
+        addFunction(TIME_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_TIME, true);
+        addFunction(TIME_DEFAULT_NULL_CONSTRUCTOR_WITH_FORMAT, NullableTypeComputer.INSTANCE_TIME, true);
+        addFunction(DATETIME_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_DATE_TIME, true);
+        addFunction(DATETIME_DEFAULT_NULL_CONSTRUCTOR_WITH_FORMAT, NullableTypeComputer.INSTANCE_DATE_TIME, true);
+        addFunction(DURATION_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_DURATION, true);
+        addFunction(DAY_TIME_DURATION_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_DAY_TIME_DURATION, true);
+        addFunction(YEAR_MONTH_DURATION_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_YEAR_MONTH_DURATION,
                 true);
-        addPrivateFunction(DURATION_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_DURATION, true);
-        addPrivateFunction(DAY_TIME_DURATION_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_DAY_TIME_DURATION,
-                true);
-        addPrivateFunction(YEAR_MONTH_DURATION_DEFAULT_NULL_CONSTRUCTOR,
-                NullableTypeComputer.INSTANCE_YEAR_MONTH_DURATION, true);
-        addPrivateFunction(UUID_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_UUID, true);
-        addPrivateFunction(BINARY_BASE64_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_BINARY, true);
+        addFunction(UUID_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_UUID, true);
+        addFunction(BINARY_BASE64_DEFAULT_NULL_CONSTRUCTOR, NullableTypeComputer.INSTANCE_BINARY, true);
 
         addPrivateFunction(NUMERIC_UNARY_MINUS, NumericUnaryTypeComputer.INSTANCE, true);
         addPrivateFunction(NUMERIC_SUBTRACT, NumericAddSubMulDivTypeComputer.INSTANCE_SUB, true);