diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 5161bac5457..4dad36820d0 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -370,10 +370,14 @@ do_analyze_rel(Relation onerel, VacuumStmt *vacstmt,
 	/*
 	 * Determine which columns to analyze
 	 *
-	 * Note that system attributes are never analyzed.
+	 * Note that system attributes are never analyzed, so we just reject them
+	 * at the lookup stage.  We also reject duplicate column mentions.  (We
+	 * could alternatively ignore duplicates, but analyzing a column twice
+	 * won't work; we'd end up making a conflicting update in pg_statistic.)
 	 */
 	if (vacstmt->va_cols != NIL)
 	{
+		Bitmapset  *unique_cols = NULL;
 		ListCell   *le;
 
 		vacattrstats = (VacAttrStats **) palloc(list_length(vacstmt->va_cols) *
@@ -389,6 +393,13 @@ do_analyze_rel(Relation onerel, VacuumStmt *vacstmt,
 						(errcode(ERRCODE_UNDEFINED_COLUMN),
 					errmsg("column \"%s\" of relation \"%s\" does not exist",
 						   col, RelationGetRelationName(onerel))));
+			if (bms_is_member(i, unique_cols))
+				ereport(ERROR,
+						(errcode(ERRCODE_DUPLICATE_COLUMN),
+						 errmsg("column \"%s\" of relation \"%s\" is specified twice",
+								col, RelationGetRelationName(onerel))));
+			unique_cols = bms_add_member(unique_cols, i);
+
 			vacattrstats[tcnt] = examine_attribute(onerel, i, NULL);
 			if (vacattrstats[tcnt] != NULL)
 				tcnt++;
diff --git a/src/test/regress/expected/vacuum.out b/src/test/regress/expected/vacuum.out
index d2d75038286..bf5034ad685 100644
--- a/src/test/regress/expected/vacuum.out
+++ b/src/test/regress/expected/vacuum.out
@@ -79,5 +79,10 @@ ERROR:  ANALYZE cannot be executed from VACUUM or ANALYZE
 CONTEXT:  SQL function "do_analyze" statement 1
 SQL function "wrap_do_analyze" statement 1
 VACUUM FULL vactst;
+-- check behavior with duplicate column mentions
+VACUUM ANALYZE vaccluster(i,i);
+ERROR:  column "i" of relation "vaccluster" is specified twice
+ANALYZE vaccluster(i,i);
+ERROR:  column "i" of relation "vaccluster" is specified twice
 DROP TABLE vaccluster;
 DROP TABLE vactst;
diff --git a/src/test/regress/sql/vacuum.sql b/src/test/regress/sql/vacuum.sql
index f8412016cf3..0d58376b943 100644
--- a/src/test/regress/sql/vacuum.sql
+++ b/src/test/regress/sql/vacuum.sql
@@ -60,5 +60,9 @@ VACUUM FULL pg_database;
 VACUUM FULL vaccluster;
 VACUUM FULL vactst;
 
+-- check behavior with duplicate column mentions
+VACUUM ANALYZE vaccluster(i,i);
+ANALYZE vaccluster(i,i);
+
 DROP TABLE vaccluster;
 DROP TABLE vactst;