diff --git a/asterix-om/src/main/java/edu/uci/ics/asterix/om/functions/AsterixBuiltinFunctions.java b/asterix-om/src/main/java/edu/uci/ics/asterix/om/functions/AsterixBuiltinFunctions.java
index 6f5a95f..e95cb6f 100644
--- a/asterix-om/src/main/java/edu/uci/ics/asterix/om/functions/AsterixBuiltinFunctions.java
+++ b/asterix-om/src/main/java/edu/uci/ics/asterix/om/functions/AsterixBuiltinFunctions.java
@@ -429,7 +429,7 @@
 
         // and then, Asterix builtin functions
         add(ANY_COLLECTION_MEMBER, NonTaggedCollectionMemberResultType.INSTANCE);
-        add(AVG, OptionalADoubleTypeComputer.INSTANCE);
+        addPrivateFunction(AVG, OptionalADoubleTypeComputer.INSTANCE);
         add(BOOLEAN_CONSTRUCTOR, UnaryBooleanOrNullFunctionTypeComputer.INSTANCE);
         add(CARET, NonTaggedNumericAddSubMulDivTypeComputer.INSTANCE);
         add(CIRCLE_CONSTRUCTOR, OptionalACircleTypeComputer.INSTANCE);
@@ -451,7 +451,7 @@
             }
         });
         add(CONTAINS, ABooleanTypeComputer.INSTANCE);
-        add(COUNT, AInt32TypeComputer.INSTANCE);
+        addPrivateFunction(COUNT, AInt32TypeComputer.INSTANCE);
         add(COUNTHASHED_GRAM_TOKENS, OrderedListOfAInt32TypeComputer.INSTANCE);
         add(COUNTHASHED_WORD_TOKENS, OrderedListOfAInt32TypeComputer.INSTANCE);
         add(CREATE_CIRCLE, ACircleTypeComputer.INSTANCE);
@@ -486,7 +486,7 @@
         add(GET_HANDLE, null); // TODO
         add(GET_ITEM, NonTaggedGetItemResultType.INSTANCE);
         add(GET_DATA, null); // TODO
-        add(GLOBAL_AVG, OptionalADoubleTypeComputer.INSTANCE);
+        addPrivateFunction(GLOBAL_AVG, OptionalADoubleTypeComputer.INSTANCE);
         add(GRAM_TOKENS, OrderedListOfAStringTypeComputer.INSTANCE);
         add(GLOBAL_AVG, OptionalADoubleTypeComputer.INSTANCE);
         add(HASHED_GRAM_TOKENS, OrderedListOfAInt32TypeComputer.INSTANCE);
@@ -507,11 +507,11 @@
         add(LIKE, BinaryBooleanOrNullFunctionTypeComputer.INSTANCE);
         add(LINE_CONSTRUCTOR, OptionalALineTypeComputer.INSTANCE);
         add(LISTIFY, OrderedListConstructorResultType.INSTANCE);
-        add(LOCAL_AVG, NonTaggedLocalAvgTypeComputer.INSTANCE);
+        addPrivateFunction(LOCAL_AVG, NonTaggedLocalAvgTypeComputer.INSTANCE);
         add(MAKE_FIELD_INDEX_HANDLE, null); // TODO
         add(MAKE_FIELD_NAME_HANDLE, null); // TODO
-        add(MAX, NonTaggedSumTypeComputer.INSTANCE);
-        add(MIN, NonTaggedSumTypeComputer.INSTANCE);
+        addPrivateFunction(MAX, NonTaggedSumTypeComputer.INSTANCE);
+        addPrivateFunction(MIN, NonTaggedSumTypeComputer.INSTANCE);
         add(NON_EMPTY_STREAM, ABooleanTypeComputer.INSTANCE);
         add(NULL_CONSTRUCTOR, ANullTypeComputer.INSTANCE);
         add(NUMERIC_UNARY_MINUS, NonTaggedUnaryMinusTypeComputer.INSTANCE);
@@ -617,7 +617,7 @@
             }
         });
         add(SUBSTRING, SubstringTypeComputer.INSTANCE);
-        add(SUM, NonTaggedSumTypeComputer.INSTANCE);
+        addPrivateFunction(SUM, NonTaggedSumTypeComputer.INSTANCE);
         add(SWITCH_CASE, NonTaggedSwitchCaseComputer.INSTANCE);
         add(REG_EXP, ABooleanTypeComputer.INSTANCE);
         add(INJECT_FAILURE, InjectFailureTypeComputer.INSTANCE);
@@ -816,6 +816,13 @@
         asterixFunctionIdToInfo.put(fi, functionInfo);
     }
 
+    private static IFunctionInfo addPrivateFunction(FunctionIdentifier fi, IResultTypeComputer typeComputer) {
+        IFunctionInfo functionInfo = getAsterixFunctionInfo(fi);
+        builtinFunctionsSet.put(functionInfo, functionInfo);
+        funTypeComputer.put(functionInfo, typeComputer);
+        return functionInfo;
+    }
+
     private static void addAgg(FunctionIdentifier fi) {
         builtinAggregateFunctions.add(getAsterixFunctionInfo(fi));
     }