diff --git a/mysql-test/r/heap_btree.result b/mysql-test/r/heap_btree.result
index c20dfbe80d2..65ced2bd24e 100644
--- a/mysql-test/r/heap_btree.result
+++ b/mysql-test/r/heap_btree.result
@@ -336,4 +336,11 @@ a	b
 NULL	NULL
 NULL	1
 drop table t1;
+#
+# bug#39918 - memory (heap) engine crashing while executing self join with delete
+#
+CREATE TABLE t1(a INT, KEY USING BTREE (a)) ENGINE=MEMORY;
+INSERT INTO t1 VALUES(1),(1);
+DELETE a1 FROM t1 AS a1, t1 AS a2 WHERE a1.a=a2.a;
+DROP TABLE t1;
 End of 5.0 tests
diff --git a/mysql-test/t/heap_btree.test b/mysql-test/t/heap_btree.test
index 76c319c0bc1..710c8411751 100644
--- a/mysql-test/t/heap_btree.test
+++ b/mysql-test/t/heap_btree.test
@@ -253,5 +253,13 @@ insert into t1 values (1, 1), (3, 3), (2, 2), (NULL, 1), (NULL, NULL), (0, 0);
 select * from t1 where a is null;
 drop table t1;
 
+-- echo #
+-- echo # bug#39918 - memory (heap) engine crashing while executing self join with delete
+-- echo #
+
+CREATE TABLE t1(a INT, KEY USING BTREE (a)) ENGINE=MEMORY;
+INSERT INTO t1 VALUES(1),(1);
+DELETE a1 FROM t1 AS a1, t1 AS a2 WHERE a1.a=a2.a;
+DROP TABLE t1;
 --echo End of 5.0 tests
 
diff --git a/sql/sql_delete.cc b/sql/sql_delete.cc
index a757b7c28a5..5307a4426c5 100644
--- a/sql/sql_delete.cc
+++ b/sql/sql_delete.cc
@@ -503,6 +503,11 @@ int mysql_multi_delete_prepare(THD *thd)
       }
     }
   }
+  /*
+    Reset the exclude flag to false so it doesn't interfare
+    with further calls to unique_table
+  */
+  lex->select_lex.exclude_from_table_unique_test= FALSE;
   DBUG_RETURN(FALSE);
 }
 
@@ -538,11 +543,24 @@ multi_delete::initialize_tables(JOIN *join)
     DBUG_RETURN(1);
 
   table_map tables_to_delete_from=0;
+  delete_while_scanning= 1;
   for (walk= delete_tables; walk; walk= walk->next_local)
+  {
     tables_to_delete_from|= walk->table->map;
+    if (delete_while_scanning &&
+        unique_table(thd, walk, join->tables_list, false))
+    {
+      /*
+        If the table we are going to delete from appears
+        in join, we need to defer delete. So the delete
+        doesn't interfers with the scaning of results.
+      */
+      delete_while_scanning= 0;
+    }
+  }
+
 
   walk= delete_tables;
-  delete_while_scanning= 1;
   for (JOIN_TAB *tab=join->join_tab, *end=join->join_tab+join->tables;
        tab < end;
        tab++)
diff --git a/tests/mysql_client_test.c b/tests/mysql_client_test.c
index 9e026a27b6d..9dfacb7436d 100644
--- a/tests/mysql_client_test.c
+++ b/tests/mysql_client_test.c
@@ -3971,6 +3971,10 @@ static void test_fetch_date()
 
   myheader("test_fetch_date");
 
+  /* Will not work if sql_mode is NO_ZERO_DATE (implicit if TRADITIONAL) /*/
+  rc= mysql_query(mysql, "SET SQL_MODE=''");
+  myquery(rc);
+
   rc= mysql_query(mysql, "DROP TABLE IF EXISTS test_bind_result");
   myquery(rc);
 
@@ -4685,6 +4689,9 @@ static void test_stmt_close()
   /* set AUTOCOMMIT to ON*/
   mysql_autocommit(lmysql, TRUE);
 
+  rc= mysql_query(lmysql, "SET SQL_MODE = ''");
+  myquery(rc);
+
   rc= mysql_query(lmysql, "DROP TABLE IF EXISTS test_stmt_close");
   myquery(rc);
 
@@ -11855,6 +11862,9 @@ static void test_bug6058()
 
   myheader("test_bug6058");
 
+  rc= mysql_query(mysql, "SET SQL_MODE=''");
+  myquery(rc);
+
   stmt_text= "SELECT CAST('0000-00-00' AS DATE)";
 
   rc= mysql_real_query(mysql, stmt_text, (uint) strlen(stmt_text));
@@ -13026,6 +13036,9 @@ static void test_bug8378()
   if (!opt_silent)
     fprintf(stdout, " OK");
 
+  rc= mysql_query(lmysql, "SET SQL_MODE=''");
+  myquery(rc);
+
   len= mysql_real_escape_string(lmysql, out, TEST_BUG8378_IN, 4);
 
   /* No escaping should have actually happened. */
@@ -16056,6 +16069,11 @@ static void test_bug31669()
   rc= mysql_query(mysql, query);
   myquery(rc);
 
+  strxmov(query, "GRANT ALL PRIVILEGES ON *.* TO '", user, "'@'localhost' IDENTIFIED BY "
+                 "'", buff, "' WITH GRANT OPTION", NullS);
+  rc= mysql_query(mysql, query);
+  myquery(rc);
+
   rc= mysql_query(mysql, "FLUSH PRIVILEGES");
   myquery(rc);
 
@@ -16093,7 +16111,7 @@ static void test_bug31669()
   strxmov(query, "DELETE FROM mysql.user WHERE User='", user, "'", NullS);
   rc= mysql_query(mysql, query);
   myquery(rc);
-  DIE_UNLESS(mysql_affected_rows(mysql) == 1);
+  DIE_UNLESS(mysql_affected_rows(mysql) == 2);
 #endif
 
   DBUG_VOID_RETURN;