diff --git a/ext/pdo_firebird/firebird_driver.c b/ext/pdo_firebird/firebird_driver.c
index 65034179ddf..0a54bf90e7b 100644
--- a/ext/pdo_firebird/firebird_driver.c
+++ b/ext/pdo_firebird/firebird_driver.c
@@ -1250,8 +1250,7 @@ static int pdo_firebird_get_attribute(pdo_dbh_t *dbh, zend_long attr, zval *val)
 				ZVAL_STRING(val, tmp);
 				return 1;
 			}
-			/* TODO Check this is correct? */
-			ZEND_FALLTHROUGH;
+			return -1;
 
 		case PDO_ATTR_FETCH_TABLE_NAMES:
 			ZVAL_BOOL(val, H->fetch_table_names);