diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 52dd400..2a8b78d 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -901,7 +901,7 @@ TypeIsVisible(Oid typid)
  */
 FuncCandidateList
 FuncnameGetCandidates(List *names, int nargs, List *argnames,
-					  bool expand_variadic, bool expand_defaults,
+					  bool expand_variadic, bool expand_defaults, char prokind,
 					  bool missing_ok)
 {
 	FuncCandidateList resultList = NULL;
@@ -948,6 +948,10 @@ FuncnameGetCandidates(List *names, int nargs, List *argnames,
 		int		   *argnumbers = NULL;
 		FuncCandidateList newResult;
 
+		/* Match prokind if specific one is requested. */
+		if (prokind != PROKIND_INVALID && prokind != procform->prokind)
+			continue;
+
 		if (OidIsValid(namespaceId))
 		{
 			/* Consider only procs in specified namespace */
@@ -1409,7 +1413,8 @@ FunctionIsVisible(Oid funcid)
 		visible = false;
 
 		clist = FuncnameGetCandidates(list_make1(makeString(proname)),
-									  nargs, NIL, false, false, false);
+									  nargs, NIL, false, false,
+									  PROKIND_INVALID, false);
 
 		for (; clist; clist = clist->next)
 		{
diff --git a/src/backend/catalog/pg_aggregate.c b/src/backend/catalog/pg_aggregate.c
index 50d8d81..27530b0 100644
--- a/src/backend/catalog/pg_aggregate.c
+++ b/src/backend/catalog/pg_aggregate.c
@@ -803,6 +803,7 @@ lookup_agg_function(List *fnName,
 	 */
 	fdresult = func_get_detail(fnName, NIL, NIL,
 							   nargs, input_types, false, false,
+							   PROKIND_INVALID,
 							   &fnOid, rettype, &retset,
 							   &nvargs, &vatype,
 							   &true_oid_array, NULL);
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index ea5d521..5784691 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -247,6 +247,7 @@ ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs,
 	fdresult = func_get_detail(funcname, fargs, argnames, nargs,
 							   actual_arg_types,
 							   !func_variadic, true,
+							   proc_call ? PROKIND_PROCEDURE : PROKIND_INVALID,
 							   &funcid, &rettype, &retset,
 							   &nvargs, &vatype,
 							   &declared_arg_types, &argdefaults);
@@ -1316,6 +1317,7 @@ func_get_detail(List *funcname,
 				Oid *argtypes,
 				bool expand_variadic,
 				bool expand_defaults,
+				char prokind,
 				Oid *funcid,	/* return value */
 				Oid *rettype,	/* return value */
 				bool *retset,	/* return value */
@@ -1342,7 +1344,7 @@ func_get_detail(List *funcname,
 
 	/* Get list of possible candidates from namespace search */
 	raw_candidates = FuncnameGetCandidates(funcname, nargs, fargnames,
-										   expand_variadic, expand_defaults,
+										   expand_variadic, expand_defaults, prokind,
 										   false);
 
 	/*
@@ -1978,7 +1980,8 @@ LookupFuncName(List *funcname, int nargs, const Oid *argtypes, bool noError)
 	/* Passing NULL for argtypes is no longer allowed */
 	Assert(argtypes);
 
-	clist = FuncnameGetCandidates(funcname, nargs, NIL, false, false, noError);
+	clist = FuncnameGetCandidates(funcname, nargs, NIL, false, false,
+								  PROKIND_INVALID, noError);
 
 	/*
 	 * If no arguments were specified, the name must yield a unique candidate.
diff --git a/src/backend/utils/adt/regproc.c b/src/backend/utils/adt/regproc.c
index a007982..6fb93e0 100644
--- a/src/backend/utils/adt/regproc.c
+++ b/src/backend/utils/adt/regproc.c
@@ -94,7 +94,8 @@ regprocin(PG_FUNCTION_ARGS)
 	 * pg_proc entries in the current search path.
 	 */
 	names = stringToQualifiedNameList(pro_name_or_oid);
-	clist = FuncnameGetCandidates(names, -1, NIL, false, false, false);
+	clist = FuncnameGetCandidates(names, -1, NIL, false, false,
+								  PROKIND_INVALID, false);
 
 	if (clist == NULL)
 		ereport(ERROR,
@@ -128,7 +129,8 @@ to_regproc(PG_FUNCTION_ARGS)
 	 * entries in the current search path.
 	 */
 	names = stringToQualifiedNameList(pro_name);
-	clist = FuncnameGetCandidates(names, -1, NIL, false, false, true);
+	clist = FuncnameGetCandidates(names, -1, NIL, false, false,
+								  PROKIND_INVALID, true);
 
 	if (clist == NULL || clist->next != NULL)
 		PG_RETURN_NULL();
@@ -176,7 +178,8 @@ regprocout(PG_FUNCTION_ARGS)
 			 * qualify it.
 			 */
 			clist = FuncnameGetCandidates(list_make1(makeString(proname)),
-										  -1, NIL, false, false, false);
+										  -1, NIL, false, false,
+										  PROKIND_INVALID, false);
 			if (clist != NULL && clist->next == NULL &&
 				clist->oid == proid)
 				nspname = NULL;
@@ -263,7 +266,8 @@ regprocedurein(PG_FUNCTION_ARGS)
 	 */
 	parseNameAndArgTypes(pro_name_or_oid, false, &names, &nargs, argtypes);
 
-	clist = FuncnameGetCandidates(names, nargs, NIL, false, false, false);
+	clist = FuncnameGetCandidates(names, nargs, NIL, false, false,
+								  PROKIND_INVALID, false);
 
 	for (; clist; clist = clist->next)
 	{
@@ -302,7 +306,8 @@ to_regprocedure(PG_FUNCTION_ARGS)
 	 */
 	parseNameAndArgTypes(pro_name, false, &names, &nargs, argtypes);
 
-	clist = FuncnameGetCandidates(names, nargs, NIL, false, false, true);
+	clist = FuncnameGetCandidates(names, nargs, NIL, false, false,
+								  PROKIND_INVALID, true);
 
 	for (; clist; clist = clist->next)
 	{
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index b0559ca..03bf868 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -10755,7 +10755,7 @@ generate_function_name(Oid funcid, int nargs, List *argnames, Oid *argtypes,
 	if (!force_qualify)
 		p_result = func_get_detail(list_make1(makeString(proname)),
 								   NIL, argnames, nargs, argtypes,
-								   !use_variadic, true,
+								   !use_variadic, true, PROKIND_INVALID,
 								   &p_funcid, &p_rettype,
 								   &p_retset, &p_nvargs, &p_vatype,
 								   &p_true_typeids, NULL);
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index 5f8cf49..f12edc8 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -72,6 +72,7 @@ extern FuncCandidateList FuncnameGetCandidates(List *names,
 					  int nargs, List *argnames,
 					  bool expand_variadic,
 					  bool expand_defaults,
+					  char prokind,
 					  bool missing_ok);
 extern bool FunctionIsVisible(Oid funcid);
 
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index bfc9009..8821bb7 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -5578,6 +5578,7 @@ DESCR("hash partition CHECK constraint");
 /*
  * Symbolic values for prokind column
  */
+#define PROKIND_INVALID '\0'
 #define PROKIND_FUNCTION 'f'
 #define PROKIND_AGGREGATE 'a'
 #define PROKIND_WINDOW 'w'
diff --git a/src/include/parser/parse_func.h b/src/include/parser/parse_func.h
index 2e3810f..737852d 100644
--- a/src/include/parser/parse_func.h
+++ b/src/include/parser/parse_func.h
@@ -39,6 +39,7 @@ extern FuncDetailCode func_get_detail(List *funcname,
 				List *fargs, List *fargnames,
 				int nargs, Oid *argtypes,
 				bool expand_variadic, bool expand_defaults,
+				char prokind,
 				Oid *funcid, Oid *rettype,
 				bool *retset, int *nvargs, Oid *vatype,
 				Oid **true_typeids, List **argdefaults);