diff --git a/mysql-test/r/create.result b/mysql-test/r/create.result
index b8723a87661..c7997369f4d 100644
--- a/mysql-test/r/create.result
+++ b/mysql-test/r/create.result
@@ -1559,6 +1559,8 @@ SHOW INDEX FROM t1;
 Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment
 t1	1	c1	1	c1	A	NULL	NULL	NULL	YES	BTREE	
 DROP TABLE t1;
+create user mysqltest_1@'test@test';
+ERROR HY000: Malformed hostname (illegal symbol: '@')
 CREATE TABLE t1 (a INTEGER AUTO_INCREMENT PRIMARY KEY, b INTEGER NOT NULL);
 INSERT IGNORE INTO t1 (b) VALUES (5);
 CREATE TABLE IF NOT EXISTS t2 (a INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY)
diff --git a/mysql-test/t/create.test b/mysql-test/t/create.test
index 60d98fce490..2eeca1eea90 100644
--- a/mysql-test/t/create.test
+++ b/mysql-test/t/create.test
@@ -1175,6 +1175,11 @@ CREATE TABLE t1(c1 VARCHAR(33), KEY USING HASH (c1) USING BTREE) ENGINE=MEMORY;
 SHOW INDEX FROM t1;
 DROP TABLE t1;
 
+#
+# Bug#35924 DEFINER should be stored 'quoted' in I_S
+#
+--error ER_UNKNOWN_ERROR
+create user mysqltest_1@'test@test';
 
 #
 # Bug#38821: Assert table->auto_increment_field_not_null failed in open_table()
diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index f2b2806ea60..d11f2838e3a 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -803,6 +803,7 @@ bool check_string_byte_length(LEX_STRING *str, const char *err_msg,
 bool check_string_char_length(LEX_STRING *str, const char *err_msg,
                               uint max_char_length, CHARSET_INFO *cs,
                               bool no_error);
+bool check_host_name(LEX_STRING *str);
 
 bool parse_sql(THD *thd,
                Parser_state *parser_state,
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 30fef9c7ee7..a710b80b4e0 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -7503,6 +7503,39 @@ int test_if_data_home_dir(const char *dir)
 C_MODE_END
 
 
+/**
+  Check that host name string is valid.
+
+  @param[in] str string to be checked
+
+  @return             Operation status
+    @retval  FALSE    host name is ok
+    @retval  TRUE     host name string is longer than max_length or
+                      has invalid symbols
+*/
+
+bool check_host_name(LEX_STRING *str)
+{
+  const char *name= str->str;
+  const char *end= str->str + str->length;
+  if (check_string_byte_length(str, ER(ER_HOSTNAME), HOSTNAME_LENGTH))
+    return TRUE;
+
+  while (name != end)
+  {
+    if (*name == '@')
+    {
+      my_printf_error(ER_UNKNOWN_ERROR, 
+                      "Malformed hostname (illegal symbol: '%c')", MYF(0),
+                      *name);
+      return TRUE;
+    }
+    name++;
+  }
+  return FALSE;
+}
+
+
 extern int MYSQLparse(void *thd); // from sql_yacc.cc
 
 
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index 278fe88c336..8d9b3a2d4b5 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -11301,8 +11301,7 @@ user:
             if (check_string_char_length(&$$->user, ER(ER_USERNAME),
                                          USERNAME_CHAR_LENGTH,
                                          system_charset_info, 0) ||
-                check_string_byte_length(&$$->host, ER(ER_HOSTNAME),
-                                         HOSTNAME_LENGTH))
+                check_host_name(&$$->host))
               MYSQL_YYABORT;
           }
         | CURRENT_USER optional_braces