diff --git a/src/conn/mod.rs b/src/conn/mod.rs
index ed33e40..dfc5157 100644
--- a/src/conn/mod.rs
+++ b/src/conn/mod.rs
@@ -466,6 +466,7 @@ impl Conn {
     }
 
     fn handle_err(&mut self) {
+        self.0.status_flags = StatusFlags::empty();
         self.0.has_results = false;
         self.0.ok_packet = None;
     }
@@ -1146,9 +1147,16 @@ impl Drop for Conn {
 #[allow(non_snake_case)]
 mod test {
     mod my_conn {
-        use std::{collections::HashMap, io::Write, iter, process};
+        use std::{
+            collections::HashMap, io::Write, iter, process, sync::mpsc::sync_channel,
+            time::Duration,
+        };
 
-        use mysql_common::{binlog::events::EventData, packets::binlog_request::BinlogRequest};
+        use mysql_common::{
+            binlog::events::EventData, packets::binlog_request::BinlogRequest,
+            value::json::Serialized,
+        };
+        use serde_json::json;
 
         use crate::{
             from_row, from_value, params,
@@ -1754,6 +1762,35 @@ mod test {
                 .unwrap();
         }
 
+        #[test]
+        fn issue_285() {
+            let (tx, rx) = sync_channel::<()>(0);
+
+            let handle = std::thread::spawn(move || {
+                let mut conn = Conn::new(get_opts()).unwrap();
+                const INVALID_SQL: &str = r#"
+                CREATE TEMPORARY TABLE IF NOT EXISTS `user_details` (
+                    `user_id` int(11) NOT NULL AUTO_INCREMENT,
+                    `username` varchar(255) DEFAULT NULL,
+                    `first_name` varchar(50) DEFAULT NULL,
+                    `last_name` varchar(50) DEFAULT NULL,
+                    PRIMARY KEY (`user_id`)
+                );
+
+                INSERT INTO `user_details` (`user_id`, `username`, `first_name`, `last_name`)
+                VALUES (1, 'rogers63', 'david')
+                "#;
+
+                conn.query_iter(INVALID_SQL).unwrap();
+                tx.send(()).unwrap();
+            });
+
+            match rx.recv_timeout(Duration::from_secs(100_000)) {
+                Ok(_) => handle.join().unwrap(),
+                Err(_) => panic!("test failed"),
+            }
+        }
+
         #[test]
         fn should_work_with_named_params() {
             let mut conn = Conn::new(get_opts()).unwrap();
diff --git a/src/conn/query_result.rs b/src/conn/query_result.rs
index 4e38e54..9bd35ac 100644
--- a/src/conn/query_result.rs
+++ b/src/conn/query_result.rs
@@ -136,12 +136,10 @@ impl<'c, 't, 'tc, T: crate::prelude::Protocol> QueryResult<'c, 't, 'tc, T> {
     ///
     /// **Requires:** `self.state == OnBoundary`
     fn handle_next(&mut self) {
-        if cfg!(debug_assertions) {
-            if let SetIteratorState::OnBoundary = self.state {
-            } else {
-                panic!("self.state == OnBoundary");
-            }
-        }
+        debug_assert!(
+            matches!(self.state, SetIteratorState::OnBoundary),
+            "self.state != OnBoundary"
+        );
 
         if self.conn.more_results_exists() {
             match self.conn.handle_result_set() {
diff --git a/src/lib.rs b/src/lib.rs
index f30cec1..e460c0a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -756,7 +756,7 @@
 #![crate_name = "mysql"]
 #![crate_type = "rlib"]
 #![crate_type = "dylib"]
-#![cfg_attr(feature = "nightly", feature(test, const_fn))]
+#![cfg_attr(feature = "nightly", feature(test))]
 #[cfg(feature = "nightly")]
 extern crate test;