diff --git a/pkg/sql/logictest/testdata/logic_test/alter_primary_key b/pkg/sql/logictest/testdata/logic_test/alter_primary_key
index 3125f42d4b21..fb4f94154be9 100644
--- a/pkg/sql/logictest/testdata/logic_test/alter_primary_key
+++ b/pkg/sql/logictest/testdata/logic_test/alter_primary_key
@@ -4,6 +4,9 @@ CREATE TABLE t (x INT PRIMARY KEY, y INT NOT NULL, z INT NOT NULL, w INT, INDEX
 statement ok
 INSERT INTO t VALUES (1, 2, 3, 4), (5, 6, 7, 8)
 
+statement error pgcode 0A000 .* contains duplicate column \"y\"
+ALTER TABLE t ALTER PRIMARY KEY USING COLUMNS (y, y)
+
 statement ok
 ALTER TABLE t ALTER PRIMARY KEY USING COLUMNS (y, z)
 
diff --git a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_alter_primary_key.go b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_alter_primary_key.go
index 9fc2023cd349..b50f0f304184 100644
--- a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_alter_primary_key.go
+++ b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_alter_primary_key.go
@@ -206,6 +206,7 @@ func checkForEarlyExit(b BuildCtx, tbl *scpb.Table, t alterPrimaryKeySpec) {
 		panic(err)
 	}
 
+	usedColumns := make(map[tree.Name]bool, len(t.Columns))
 	for _, col := range t.Columns {
 		if col.Column == "" && col.Expr != nil {
 			panic(errors.WithHint(
@@ -217,6 +218,11 @@ func checkForEarlyExit(b BuildCtx, tbl *scpb.Table, t alterPrimaryKeySpec) {
 				"use columns instead",
 			))
 		}
+		if usedColumns[col.Column] {
+			panic(pgerror.Newf(pgcode.FeatureNotSupported,
+				"new primary key contains duplicate column %q", col.Column))
+		}
+		usedColumns[col.Column] = true
 
 		colElems := b.ResolveColumn(tbl.TableID, col.Column, ResolveParams{
 			IsExistenceOptional: false,