diff --git a/pkg/sql/pgwire/testdata/pgtest/notice b/pkg/sql/pgwire/testdata/pgtest/notice
index e60704db2a91..b1bdffafbf42 100644
--- a/pkg/sql/pgwire/testdata/pgtest/notice
+++ b/pkg/sql/pgwire/testdata/pgtest/notice
@@ -55,7 +55,7 @@ Query {"String": "DROP INDEX t_x_idx"}
 until crdb_only
 CommandComplete
 ----
-{"Severity":"NOTICE","SeverityUnlocalized":"NOTICE","Code":"00000","Message":"the data for dropped indexes is reclaimed asynchronously","Detail":"","Hint":"The reclamation delay can be customized in the zone configuration for the table.","Position":0,"InternalPosition":0,"InternalQuery":"","Where":"","SchemaName":"","TableName":"","ColumnName":"","DataTypeName":"","ConstraintName":"","File":"drop_index.go","Line":66,"Routine":"DropIndex","UnknownFields":null}
+{"Severity":"NOTICE","SeverityUnlocalized":"NOTICE","Code":"00000","Message":"the data for dropped indexes is reclaimed asynchronously","Detail":"","Hint":"The reclamation delay can be customized in the zone configuration for the table.","Position":0,"InternalPosition":0,"InternalQuery":"","Where":"","SchemaName":"","TableName":"","ColumnName":"","DataTypeName":"","ConstraintName":"","File":"drop_index.go","Line":68,"Routine":"DropIndex","UnknownFields":null}
 {"Type":"CommandComplete","CommandTag":"DROP INDEX"}
 
 until noncrdb_only
diff --git a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_drop_column.go b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_drop_column.go
index 77931bc83b85..b5d3e9d63d49 100644
--- a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_drop_column.go
+++ b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/alter_table_drop_column.go
@@ -13,6 +13,7 @@ package scbuildstmt
 import (
 	"sort"
 
+	"github.com/cockroachdb/cockroach/pkg/clusterversion"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/colinfo"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descpb"
@@ -255,6 +256,12 @@ func dropColumn(
 			}
 			dropCascadeDescriptor(b, e.FunctionID)
 		case *scpb.UniqueWithoutIndexConstraint:
+			// Until the appropriate version gate is hit, we still do not allow
+			// dropping unique without index constraints.
+			if !b.ClusterSettings().Version.IsActive(b, clusterversion.V23_1) {
+				panic(scerrors.NotImplementedErrorf(nil, "dropping without"+
+					"index constraints is not allowed."))
+			}
 			constraintElems := b.QueryByID(e.TableID).Filter(hasConstraintIDAttrFilter(e.ConstraintID))
 			_, _, constraintName := scpb.FindConstraintWithoutIndexName(constraintElems.Filter(publicTargetFilter))
 			alterTableDropConstraint(b, tn, tbl, &tree.AlterTableDropConstraint{
@@ -263,6 +270,12 @@ func dropColumn(
 				DropBehavior: behavior,
 			})
 		case *scpb.UniqueWithoutIndexConstraintUnvalidated:
+			// Until the appropriate version gate is hit, we still do not allow
+			// dropping unique without index constraints.
+			if !b.ClusterSettings().Version.IsActive(b, clusterversion.V23_1) {
+				panic(scerrors.NotImplementedErrorf(nil, "dropping without"+
+					"index constraints is not allowed."))
+			}
 			constraintElems := b.QueryByID(e.TableID).Filter(hasConstraintIDAttrFilter(e.ConstraintID))
 			_, _, constraintName := scpb.FindConstraintWithoutIndexName(constraintElems.Filter(publicTargetFilter))
 			alterTableDropConstraint(b, tn, tbl, &tree.AlterTableDropConstraint{
diff --git a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/drop_index.go b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/drop_index.go
index 05a6956b1dea..80f61e244f0f 100644
--- a/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/drop_index.go
+++ b/pkg/sql/schemachanger/scbuild/internal/scbuildstmt/drop_index.go
@@ -13,11 +13,13 @@ package scbuildstmt
 import (
 	"fmt"
 
+	"github.com/cockroachdb/cockroach/pkg/clusterversion"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descpb"
 	"github.com/cockroachdb/cockroach/pkg/sql/pgwire/pgcode"
 	"github.com/cockroachdb/cockroach/pkg/sql/pgwire/pgerror"
 	"github.com/cockroachdb/cockroach/pkg/sql/pgwire/pgnotice"
 	"github.com/cockroachdb/cockroach/pkg/sql/privilege"
+	"github.com/cockroachdb/cockroach/pkg/sql/schemachanger/scerrors"
 	"github.com/cockroachdb/cockroach/pkg/sql/schemachanger/scpb"
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/catid"
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
@@ -235,6 +237,12 @@ func maybeDropDependentFKConstraints(
 	// shouldDropFK returns true if it is a dependent FK and no uniqueness-providing
 	// replacement can be found.
 	shouldDropFK := func(fkReferencedColIDs []catid.ColumnID) bool {
+		// Until the appropriate version gate is hit, we still do not allow
+		// dropping foreign keys in any the context of secondary indexes.
+		if !b.ClusterSettings().Version.IsActive(b, clusterversion.V23_1) {
+			panic(scerrors.NotImplementedErrorf(nil, "dropping FK constraints"+
+				" as a result of `DROP INDEX CASCADE` is not supported yet."))
+		}
 		return canToBeDroppedConstraintServeFK(fkReferencedColIDs) &&
 			!hasColsUniquenessConstraintOtherThan(b, tableID, fkReferencedColIDs, toBeDroppedConstraintID)
 	}