diff --git a/src/backend/utils/adt/json.c b/src/backend/utils/adt/json.c
index 7c3992661f..403610c17a 100644
--- a/src/backend/utils/adt/json.c
+++ b/src/backend/utils/adt/json.c
@@ -96,6 +96,8 @@ static void datum_to_json(Datum val, bool is_null, StringInfo result,
 static void add_json(Datum val, bool is_null, StringInfo result,
 		 Oid val_type, bool key_scalar);
 static text *catenate_stringinfo_string(StringInfo buffer, const char *addon);
+static int extract_variadic_args(FunctionCallInfo fcinfo, Datum **values,
+								 Oid **types, bool **nulls);
 
 /* the null action object used for pure validation */
 static JsonSemAction nullSemAction =
@@ -2027,6 +2029,104 @@ catenate_stringinfo_string(StringInfo buffer, const char *addon)
 	return result;
 }
 
+/*
+ * Extract a set of argument values, types and NULL markers for a given
+ * input function. This is used by json_build_object() and json_build_array()
+ * which make use of (VARIADIC "any") whose argument list depends on the
+ * caller context. When doing a VARIADIC call, the caller has provided one
+ * argument made of an array of keys, so deconstruct the array data before
+ * using it for the next processing. If no VARIADIC call is used, just fill
+ * in the status data based on all the arguments given by the caller.
+ * This function returns the number of arguments generated. In the event
+ * where the caller provided a NULL input, then the caller of this function
+ * ought to generate a NULL object as final result, so in this case, a
+ * result value of -1 is used to be able to make the difference between an
+ * empty array or object.
+ */
+static int
+extract_variadic_args(FunctionCallInfo fcinfo, Datum **values,
+					  Oid **types, bool **nulls)
+{
+	bool		variadic = get_fn_expr_variadic(fcinfo->flinfo);
+	Datum	   *values_res;
+	bool	   *nulls_res;
+	Oid		   *types_res;
+	int			nargs, i;
+
+	*values = NULL;
+	*types = NULL;
+	*nulls = NULL;
+
+	if (variadic)
+	{
+		ArrayType  *array_in;
+		Oid			element_type;
+		bool		typbyval;
+		char		typalign;
+		int16		typlen;
+
+		Assert(PG_NARGS() == 1);
+
+		if (PG_ARGISNULL(0))
+			return -1;
+
+		array_in = PG_GETARG_ARRAYTYPE_P(0);
+		element_type = ARR_ELEMTYPE(array_in);
+
+		get_typlenbyvalalign(element_type,
+							 &typlen, &typbyval, &typalign);
+		deconstruct_array(array_in, element_type, typlen, typbyval,
+						  typalign, &values_res, &nulls_res,
+						  &nargs);
+
+		/* All the elements of the array have the same type */
+		types_res = (Oid *) palloc0(nargs * sizeof(Oid));
+		for (i = 0; i < nargs; i++)
+			types_res[i] = element_type;
+	}
+	else
+	{
+		nargs = PG_NARGS();
+		nulls_res = (bool *) palloc0(nargs * sizeof(bool));
+		values_res = (Datum *) palloc0(nargs * sizeof(Datum));
+		types_res = (Oid *) palloc0(nargs * sizeof(Oid));
+
+		for (i = 0; i < nargs; i++)
+		{
+			/*
+			 * Note: since json_build_object() and json_build_array() are
+			 * declared as taking type "any", the parser will not do any type
+			 * conversion on unknown-type literals (that is, undecorated
+			 * strings or NULLs). Such values will arrive here as type
+			 * UNKNOWN, which fortunately does not matter to us, since
+			 * unknownout() works fine.
+			 */
+			nulls_res[i] = PG_ARGISNULL(i);
+			types_res[i] = get_fn_expr_argtype(fcinfo->flinfo, i);
+
+			if (!OidIsValid(types_res[i]))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("could not determine data type for argument %d",
+								i + 1)));
+
+			/* important for value, key cannot being NULL */
+			if (PG_ARGISNULL(i))
+				values_res[i] = (Datum) 0;
+			else
+				values_res[i] = PG_GETARG_DATUM(i);
+		}
+	}
+
+	/* Fill in results */
+	*values = values_res;
+	*nulls = nulls_res;
+	*types = types_res;
+
+	return nargs;
+}
+
+
 /*
  * SQL function json_build_object(variadic "any")
  */
@@ -2035,10 +2135,17 @@ json_build_object(PG_FUNCTION_ARGS)
 {
 	int			nargs = PG_NARGS();
 	int			i;
-	Datum		arg;
 	const char *sep = "";
 	StringInfo	result;
-	Oid			val_type;
+	Datum	   *args;
+	bool	   *nulls;
+	Oid		   *types;
+
+	/* build argument values to build the object */
+	nargs = extract_variadic_args(fcinfo, &args, &types, &nulls);
+
+	if (nargs < 0)
+		PG_RETURN_NULL();
 
 	if (nargs % 2 != 0)
 		ereport(ERROR,
@@ -2052,52 +2159,22 @@ json_build_object(PG_FUNCTION_ARGS)
 
 	for (i = 0; i < nargs; i += 2)
 	{
-		/*
-		 * Note: since json_build_object() is declared as taking type "any",
-		 * the parser will not do any type conversion on unknown-type literals
-		 * (that is, undecorated strings or NULLs).  Such values will arrive
-		 * here as type UNKNOWN, which fortunately does not matter to us,
-		 * since unknownout() works fine.
-		 */
 		appendStringInfoString(result, sep);
 		sep = ", ";
 
 		/* process key */
-		val_type = get_fn_expr_argtype(fcinfo->flinfo, i);
-
-		if (val_type == InvalidOid)
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("could not determine data type for argument %d",
-							i + 1)));
-
-		if (PG_ARGISNULL(i))
+		if (nulls[i])
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("argument %d cannot be null", i + 1),
 					 errhint("Object keys should be text.")));
 
-		arg = PG_GETARG_DATUM(i);
-
-		add_json(arg, false, result, val_type, true);
+		add_json(args[i], false, result, types[i], true);
 
 		appendStringInfoString(result, " : ");
 
 		/* process value */
-		val_type = get_fn_expr_argtype(fcinfo->flinfo, i + 1);
-
-		if (val_type == InvalidOid)
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("could not determine data type for argument %d",
-							i + 2)));
-
-		if (PG_ARGISNULL(i + 1))
-			arg = (Datum) 0;
-		else
-			arg = PG_GETARG_DATUM(i + 1);
-
-		add_json(arg, PG_ARGISNULL(i + 1), result, val_type, false);
+		add_json(args[i + 1], nulls[i + 1], result, types[i + 1], false);
 	}
 
 	appendStringInfoChar(result, '}');
@@ -2120,12 +2197,19 @@ json_build_object_noargs(PG_FUNCTION_ARGS)
 Datum
 json_build_array(PG_FUNCTION_ARGS)
 {
-	int			nargs = PG_NARGS();
+	int			nargs;
 	int			i;
-	Datum		arg;
 	const char *sep = "";
 	StringInfo	result;
-	Oid			val_type;
+	Datum	   *args;
+	bool	   *nulls;
+	Oid		   *types;
+
+	/* build argument values to build the array */
+	nargs = extract_variadic_args(fcinfo, &args, &types, &nulls);
+
+	if (nargs < 0)
+		PG_RETURN_NULL();
 
 	result = makeStringInfo();
 
@@ -2133,30 +2217,9 @@ json_build_array(PG_FUNCTION_ARGS)
 
 	for (i = 0; i < nargs; i++)
 	{
-		/*
-		 * Note: since json_build_array() is declared as taking type "any",
-		 * the parser will not do any type conversion on unknown-type literals
-		 * (that is, undecorated strings or NULLs).  Such values will arrive
-		 * here as type UNKNOWN, which fortunately does not matter to us,
-		 * since unknownout() works fine.
-		 */
 		appendStringInfoString(result, sep);
 		sep = ", ";
-
-		val_type = get_fn_expr_argtype(fcinfo->flinfo, i);
-
-		if (val_type == InvalidOid)
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("could not determine data type for argument %d",
-							i + 1)));
-
-		if (PG_ARGISNULL(i))
-			arg = (Datum) 0;
-		else
-			arg = PG_GETARG_DATUM(i);
-
-		add_json(arg, PG_ARGISNULL(i), result, val_type, false);
+		add_json(args[i], nulls[i], result, types[i], false);
 	}
 
 	appendStringInfoChar(result, ']');
diff --git a/src/test/regress/expected/json.out b/src/test/regress/expected/json.out
index 8573b58e7c..d0d95f2adb 100644
--- a/src/test/regress/expected/json.out
+++ b/src/test/regress/expected/json.out
@@ -1420,6 +1420,54 @@ SELECT json_build_array('a',1,'b',1.2,'c',true,'d',null,'e',json '{"x": 3, "y":
  ["a", 1, "b", 1.2, "c", true, "d", null, "e", {"x": 3, "y": [1,2,3]}]
 (1 row)
 
+SELECT json_build_array('a', NULL); -- ok
+ json_build_array 
+------------------
+ ["a", null]
+(1 row)
+
+SELECT json_build_array(VARIADIC NULL::text[]); -- ok
+ json_build_array 
+------------------
+ 
+(1 row)
+
+SELECT json_build_array(VARIADIC '{}'::text[]); -- ok
+ json_build_array 
+------------------
+ []
+(1 row)
+
+SELECT json_build_array(VARIADIC '{a,b,c}'::text[]); -- ok
+ json_build_array 
+------------------
+ ["a", "b", "c"]
+(1 row)
+
+SELECT json_build_array(VARIADIC ARRAY['a', NULL]::text[]); -- ok
+ json_build_array 
+------------------
+ ["a", null]
+(1 row)
+
+SELECT json_build_array(VARIADIC '{1,2,3,4}'::text[]); -- ok
+   json_build_array   
+----------------------
+ ["1", "2", "3", "4"]
+(1 row)
+
+SELECT json_build_array(VARIADIC '{1,2,3,4}'::int[]); -- ok
+ json_build_array 
+------------------
+ [1, 2, 3, 4]
+(1 row)
+
+SELECT json_build_array(VARIADIC '{{1,4},{2,5},{3,6}}'::int[][]); -- ok
+  json_build_array  
+--------------------
+ [1, 4, 2, 5, 3, 6]
+(1 row)
+
 SELECT json_build_object('a',1,'b',1.2,'c',true,'d',null,'e',json '{"x": 3, "y": [1,2,3]}');
                              json_build_object                              
 ----------------------------------------------------------------------------
@@ -1435,6 +1483,65 @@ SELECT json_build_object(
  {"a" : {"b" : false, "c" : 99}, "d" : {"e" : [9,8,7], "f" : {"relkind":"r","name":"pg_class"}}}
 (1 row)
 
+SELECT json_build_object('{a,b,c}'::text[]); -- error
+ERROR:  argument list must have even number of elements
+HINT:  The arguments of json_build_object() must consist of alternating keys and values.
+SELECT json_build_object('{a,b,c}'::text[], '{d,e,f}'::text[]); -- error, key cannot be array
+ERROR:  key value must be scalar, not array, composite, or json
+SELECT json_build_object('a', 'b', 'c'); -- error
+ERROR:  argument list must have even number of elements
+HINT:  The arguments of json_build_object() must consist of alternating keys and values.
+SELECT json_build_object(NULL, 'a'); -- error, key cannot be NULL
+ERROR:  argument 1 cannot be null
+HINT:  Object keys should be text.
+SELECT json_build_object('a', NULL); -- ok
+ json_build_object 
+-------------------
+ {"a" : null}
+(1 row)
+
+SELECT json_build_object(VARIADIC NULL::text[]); -- ok
+ json_build_object 
+-------------------
+ 
+(1 row)
+
+SELECT json_build_object(VARIADIC '{}'::text[]); -- ok
+ json_build_object 
+-------------------
+ {}
+(1 row)
+
+SELECT json_build_object(VARIADIC '{a,b,c}'::text[]); -- error
+ERROR:  argument list must have even number of elements
+HINT:  The arguments of json_build_object() must consist of alternating keys and values.
+SELECT json_build_object(VARIADIC ARRAY['a', NULL]::text[]); -- ok
+ json_build_object 
+-------------------
+ {"a" : null}
+(1 row)
+
+SELECT json_build_object(VARIADIC ARRAY[NULL, 'a']::text[]); -- error, key cannot be NULL
+ERROR:  argument 1 cannot be null
+HINT:  Object keys should be text.
+SELECT json_build_object(VARIADIC '{1,2,3,4}'::text[]); -- ok
+   json_build_object    
+------------------------
+ {"1" : "2", "3" : "4"}
+(1 row)
+
+SELECT json_build_object(VARIADIC '{1,2,3,4}'::int[]); -- ok
+ json_build_object  
+--------------------
+ {"1" : 2, "3" : 4}
+(1 row)
+
+SELECT json_build_object(VARIADIC '{{1,4},{2,5},{3,6}}'::int[][]); -- ok
+      json_build_object      
+-----------------------------
+ {"1" : 4, "2" : 5, "3" : 6}
+(1 row)
+
 -- empty objects/arrays
 SELECT json_build_array();
  json_build_array 
diff --git a/src/test/regress/sql/json.sql b/src/test/regress/sql/json.sql
index 346e5b8363..587bcb8dd4 100644
--- a/src/test/regress/sql/json.sql
+++ b/src/test/regress/sql/json.sql
@@ -412,6 +412,14 @@ select value, json_typeof(value)
 -- json_build_array, json_build_object, json_object_agg
 
 SELECT json_build_array('a',1,'b',1.2,'c',true,'d',null,'e',json '{"x": 3, "y": [1,2,3]}');
+SELECT json_build_array('a', NULL); -- ok
+SELECT json_build_array(VARIADIC NULL::text[]); -- ok
+SELECT json_build_array(VARIADIC '{}'::text[]); -- ok
+SELECT json_build_array(VARIADIC '{a,b,c}'::text[]); -- ok
+SELECT json_build_array(VARIADIC ARRAY['a', NULL]::text[]); -- ok
+SELECT json_build_array(VARIADIC '{1,2,3,4}'::text[]); -- ok
+SELECT json_build_array(VARIADIC '{1,2,3,4}'::int[]); -- ok
+SELECT json_build_array(VARIADIC '{{1,4},{2,5},{3,6}}'::int[][]); -- ok
 
 SELECT json_build_object('a',1,'b',1.2,'c',true,'d',null,'e',json '{"x": 3, "y": [1,2,3]}');
 
@@ -419,6 +427,19 @@ SELECT json_build_object(
        'a', json_build_object('b',false,'c',99),
        'd', json_build_object('e',array[9,8,7]::int[],
            'f', (select row_to_json(r) from ( select relkind, oid::regclass as name from pg_class where relname = 'pg_class') r)));
+SELECT json_build_object('{a,b,c}'::text[]); -- error
+SELECT json_build_object('{a,b,c}'::text[], '{d,e,f}'::text[]); -- error, key cannot be array
+SELECT json_build_object('a', 'b', 'c'); -- error
+SELECT json_build_object(NULL, 'a'); -- error, key cannot be NULL
+SELECT json_build_object('a', NULL); -- ok
+SELECT json_build_object(VARIADIC NULL::text[]); -- ok
+SELECT json_build_object(VARIADIC '{}'::text[]); -- ok
+SELECT json_build_object(VARIADIC '{a,b,c}'::text[]); -- error
+SELECT json_build_object(VARIADIC ARRAY['a', NULL]::text[]); -- ok
+SELECT json_build_object(VARIADIC ARRAY[NULL, 'a']::text[]); -- error, key cannot be NULL
+SELECT json_build_object(VARIADIC '{1,2,3,4}'::text[]); -- ok
+SELECT json_build_object(VARIADIC '{1,2,3,4}'::int[]); -- ok
+SELECT json_build_object(VARIADIC '{{1,4},{2,5},{3,6}}'::int[][]); -- ok
 
 
 -- empty objects/arrays