diff --git a/mysql-test/main/type_timestamp.result b/mysql-test/main/type_timestamp.result
index b01f37ba125..2e797cb2b42 100644
--- a/mysql-test/main/type_timestamp.result
+++ b/mysql-test/main/type_timestamp.result
@@ -2207,5 +2207,17 @@ Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` >= TIMESTAMP/*WITH LOCAL TIME ZONE*/'2024-01-01 00:00:00.000000'
 DROP TABLE t1;
 #
+# MDEV-34085 Server crash ASAN used-after-poison upon 2nd execution of PS with erroneous timestamp conversion
+#
+CREATE TABLE t1 (a int, b timestamp);
+INSERT INTO t1 VALUES (1,'2000-01-01'),(2,'2001-12-31');
+PREPARE stmt FROM 'UPDATE t1 SET a = 0 WHERE 1 IN (SELECT b FROM t1)';
+EXECUTE stmt;
+ERROR 22007: Truncated incorrect datetime value: '1'
+EXECUTE stmt;
+ERROR 22007: Truncated incorrect datetime value: '1'
+DEALLOCATE PREPARE stmt;
+DROP TABLE t1;
+#
 # End of 11.3 tests
 #
diff --git a/mysql-test/main/type_timestamp.test b/mysql-test/main/type_timestamp.test
index c39965b0c42..1b362251d76 100644
--- a/mysql-test/main/type_timestamp.test
+++ b/mysql-test/main/type_timestamp.test
@@ -1255,6 +1255,21 @@ EXPLAIN EXTENDED SELECT * FROM t1 WHERE YEAR(a) >= 2024;
 DROP TABLE t1;
 
 
+--echo #
+--echo # MDEV-34085 Server crash ASAN used-after-poison upon 2nd execution of PS with erroneous timestamp conversion
+--echo #
+
+CREATE TABLE t1 (a int, b timestamp);
+INSERT INTO t1 VALUES (1,'2000-01-01'),(2,'2001-12-31');
+PREPARE stmt FROM 'UPDATE t1 SET a = 0 WHERE 1 IN (SELECT b FROM t1)';
+--error ER_TRUNCATED_WRONG_VALUE
+EXECUTE stmt;
+--error ER_TRUNCATED_WRONG_VALUE
+EXECUTE stmt;
+DEALLOCATE PREPARE stmt;
+DROP TABLE t1;
+
+
 --echo #
 --echo # End of 11.3 tests
 --echo #
diff --git a/sql/sql_type.cc b/sql/sql_type.cc
index bd807db4bf7..4e78dab6e4a 100644
--- a/sql/sql_type.cc
+++ b/sql/sql_type.cc
@@ -7776,7 +7776,7 @@ Type_handler_datetime_common::convert_item_for_comparison(
                           Sql_condition **cond_hdl)
     {
       hit++;
-      return *level == Sql_condition::WARN_LEVEL_WARN;
+      return *level >= Sql_condition::WARN_LEVEL_WARN;
     }
   } cnt_handler;