diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c
index a823c1b370e..9247da6b2bd 100644
--- a/src/backend/parser/parse_clause.c
+++ b/src/backend/parser/parse_clause.c
@@ -56,6 +56,8 @@ sortby_nulls_hook_type  sortby_nulls_hook = NULL;
 
 optimize_explicit_cast_hook_type optimize_explicit_cast_hook = NULL;
 
+pre_transform_openxml_columns_hook_type pre_transform_openxml_columns_hook = NULL;
+
 static int	extractRemainingColumns(ParseState *pstate,
 									ParseNamespaceColumn *src_nscolumns,
 									List *src_colnames,
@@ -711,6 +713,13 @@ transformRangeTableFunc(ParseState *pstate, RangeTableFunc *rtf)
 	constructName = "XMLTABLE";
 	docType = XMLOID;
 
+	/*
+	 * Hook to allow extensions to pre-process OPENXML column definitions
+	 * before standard XMLTABLE transformation.
+	 */
+	if (pre_transform_openxml_columns_hook && tf->functype == TFT_XMLTABLE)
+		pre_transform_openxml_columns_hook(pstate, rtf);
+
 	/*
 	 * We make lateral_only names of this level visible, whether or not the
 	 * RangeTableFunc is explicitly marked LATERAL.  This is needed for SQL
diff --git a/src/include/parser/parse_clause.h b/src/include/parser/parse_clause.h
index d307e4dbdc9..ca3e0d3eb2c 100644
--- a/src/include/parser/parse_clause.h
+++ b/src/include/parser/parse_clause.h
@@ -62,4 +62,8 @@ extern PGDLLEXPORT optimize_explicit_cast_hook_type optimize_explicit_cast_hook;
 /* functions in parse_jsontable.c */
 extern ParseNamespaceItem *transformJsonTable(ParseState *pstate, JsonTable *jt);
 
+/* Hook for preprocessing OPENXML column definitions before XMLTABLE transformation */
+typedef void (*pre_transform_openxml_columns_hook_type) (ParseState *pstate, RangeTableFunc *rtf);
+extern PGDLLIMPORT pre_transform_openxml_columns_hook_type pre_transform_openxml_columns_hook;
+
 #endif							/* PARSE_CLAUSE_H */