diff --git a/go/vt/sqlparser/ast.go b/go/vt/sqlparser/ast.go
index 542a351bcb5..c5b064d0721 100644
--- a/go/vt/sqlparser/ast.go
+++ b/go/vt/sqlparser/ast.go
@@ -2196,6 +2196,9 @@ type DDL struct {
 	// Set for constraint alter statements
 	ConstraintAction string
 
+	// ConstraintIfExists is set to true if the constraint action should not fail if the constraint doesn't exist.
+	ConstraintIfExists bool
+
 	// Set for column add / drop / rename statements
 	Column ColIdent