diff --git a/mysql-test/suite/rpl/r/rpl_stm_sql_mode.result b/mysql-test/suite/rpl/r/rpl_stm_sql_mode.result
new file mode 100644
index 00000000000..fd143fc8a50
--- /dev/null
+++ b/mysql-test/suite/rpl/r/rpl_stm_sql_mode.result
@@ -0,0 +1,18 @@
+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+CREATE TABLE t1 (pk integer auto_increment , primary key (pk));
+SET SESSION SQL_MODE='traditional';
+# **** [MASTER] *****
+# action: raise DUP KEY error (error code should be set in the 
+#                              query log event)
+INSERT INTO t1 (`pk`) VALUES (1), (1);
+ERROR 23000: Duplicate entry '1' for key 'PRIMARY'
+DROP TABLE t1;
+# **** [ sync slave with master ] ****
+# assertion: sync slave with master makes slave not to stop with
+#            duplicate key error (because it has received event
+#            with expected error code).
diff --git a/mysql-test/suite/rpl/t/rpl_stm_sql_mode.test b/mysql-test/suite/rpl/t/rpl_stm_sql_mode.test
new file mode 100644
index 00000000000..d5aac4a43e2
--- /dev/null
+++ b/mysql-test/suite/rpl/t/rpl_stm_sql_mode.test
@@ -0,0 +1,24 @@
+-- source include/master-slave.inc
+-- source include/have_binlog_format_statement.inc
+
+#
+# Bug #51055    Replication failure on duplicate key + traditional SQL mode
+#
+
+CREATE TABLE t1 (pk integer auto_increment , primary key (pk));
+
+SET SESSION SQL_MODE='traditional';
+
+-- echo # **** [MASTER] *****
+-- echo # action: raise DUP KEY error (error code should be set in the 
+-- echo #                              query log event)
+-- error ER_DUP_ENTRY
+INSERT INTO t1 (`pk`) VALUES (1), (1);
+
+DROP TABLE t1;
+
+-- echo # **** [ sync slave with master ] ****
+-- echo # assertion: sync slave with master makes slave not to stop with
+-- echo #            duplicate key error (because it has received event
+-- echo #            with expected error code).
+-- sync_slave_with_master
diff --git a/sql/log.cc b/sql/log.cc
index b7313a988c4..b75650cfec7 100644
--- a/sql/log.cc
+++ b/sql/log.cc
@@ -4679,7 +4679,7 @@ int query_error_code(THD *thd, bool not_killed)
 {
   int error;
   
-  if (not_killed)
+  if (not_killed || (thd->killed == THD::KILL_BAD_DATA))
   {
     error= thd->is_error() ? thd->main_da.sql_errno() : 0;