diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 14be0882578..a7e2120e0dc 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -2783,6 +2783,15 @@ transformLockingClause(ParseState *pstate, Query *qry, LockingClause *lc,
 				++i;
 				if (!rte->inFromCl)
 					continue;
+
+				/*
+				 * A join RTE without an alias is not visible as a relation
+				 * name and needs to be skipped (otherwise it might hide a
+				 * base relation with the same name).
+				 */
+				if (rte->rtekind == RTE_JOIN && rte->alias == NULL)
+					continue;
+
 				if (strcmp(rte->eref->aliasname, thisrel->relname) == 0)
 				{
 					switch (rte->rtekind)
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index e8f7a13a0a8..4dd78e91e50 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -2412,6 +2412,14 @@ ERROR:  column t1.x does not exist
 LINE 1: select t1.x from t1 join t3 on (t1.a = t3.x);
                ^
 HINT:  Perhaps you meant to reference the column "t3.x".
+-- Test matching of locking clause with wrong alias
+select t1.*, t2.*, unnamed_join.* from
+  t1 join t2 on (t1.a = t2.a), t3 as unnamed_join
+  for update of unnamed_join;
+ a | b | a | b | x | y 
+---+---+---+---+---+---
+(0 rows)
+
 --
 -- regression test for 8.1 merge right join bug
 --
diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql
index 9404ec86bb6..b11e9280128 100644
--- a/src/test/regress/sql/join.sql
+++ b/src/test/regress/sql/join.sql
@@ -487,6 +487,12 @@ select * from t1 left join t2 on (t1.a = t2.a);
 
 select t1.x from t1 join t3 on (t1.a = t3.x);
 
+-- Test matching of locking clause with wrong alias
+
+select t1.*, t2.*, unnamed_join.* from
+  t1 join t2 on (t1.a = t2.a), t3 as unnamed_join
+  for update of unnamed_join;
+
 --
 -- regression test for 8.1 merge right join bug
 --