diff --git a/src/backend/parser/parse_type.c b/src/backend/parser/parse_type.c
index a33b59c62e..c1a937a43b 100644
--- a/src/backend/parser/parse_type.c
+++ b/src/backend/parser/parse_type.c
@@ -537,7 +537,7 @@ LookupCollation(ParseState *pstate, List *collnames, int location)
  * pstate is only used for error location purposes, and can be NULL.
  */
 Oid
-GetColumnDefCollation(ParseState *pstate, ColumnDef *coldef, Oid typeOid)
+GetColumnDefCollation(ParseState *pstate, const ColumnDef *coldef, Oid typeOid)
 {
 	Oid			result;
 	Oid			typcollation = get_typcollation(typeOid);
diff --git a/src/include/parser/parse_type.h b/src/include/parser/parse_type.h
index e5fa759120..b62e7a6ce9 100644
--- a/src/include/parser/parse_type.h
+++ b/src/include/parser/parse_type.h
@@ -36,7 +36,7 @@ extern char *TypeNameToString(const TypeName *typeName);
 extern char *TypeNameListToString(List *typenames);
 
 extern Oid	LookupCollation(ParseState *pstate, List *collnames, int location);
-extern Oid	GetColumnDefCollation(ParseState *pstate, ColumnDef *coldef, Oid typeOid);
+extern Oid	GetColumnDefCollation(ParseState *pstate, const ColumnDef *coldef, Oid typeOid);
 
 extern Type typeidType(Oid id);