diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index e0e51a0f626..b1c293d3c77 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -1223,7 +1223,7 @@ File open_binlog(IO_CACHE *log, const char *log_file_name,
                  const char **errmsg);
 
 /* mysqld.cc */
-extern void yyerror(const char*);
+extern void MYSQLerror(const char*);
 
 /* item_func.cc */
 extern bool check_reserved_words(LEX_STRING *name);
@@ -1634,7 +1634,7 @@ void free_list(I_List <i_string_pair> *list);
 void free_list(I_List <i_string> *list);
 
 /* sql_yacc.cc */
-extern int yyparse(void *thd);
+extern int MYSQLparse(void *thd);
 
 /* frm_crypt.cc */
 #ifdef HAVE_CRYPTED_FRM
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 59af5a529d0..7fcbf5134f5 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -1620,7 +1620,7 @@ static void network_init(void)
 
 #endif /*!EMBEDDED_LIBRARY*/
 
-void yyerror(const char *s)
+void MYSQLerror(const char *s)
 {
   THD *thd=current_thd;
   char *yytext= (char*) thd->lex->tok_start;
diff --git a/sql/sp.cc b/sql/sp.cc
index 87826adcb65..022417d15d1 100644
--- a/sql/sp.cc
+++ b/sql/sp.cc
@@ -268,7 +268,7 @@ db_find_routine_aux(THD *thd, int type, sp_name *name, TABLE *table)
 static int
 db_find_routine(THD *thd, int type, sp_name *name, sp_head **sphp)
 {
-  extern int yyparse(void *thd);
+  extern int MYSQLparse(void *thd);
   TABLE *table;
   const char *params, *returns, *body;
   int ret;
@@ -458,7 +458,7 @@ db_load_routine(THD *thd, int type, sp_name *name, sp_head **sphp,
   lex_start(thd, (uchar*)defstr.c_ptr(), defstr.length());
 
   thd->spcont= 0;
-  if (yyparse(thd) || thd->is_fatal_error || newlex.sphead == NULL)
+  if (MYSQLparse(thd) || thd->is_fatal_error || newlex.sphead == NULL)
   {
     sp_head *sp= newlex.sphead;
 
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index f0de4580c18..b5c1d943339 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -513,14 +513,14 @@ static inline uint int_token(const char *str,uint length)
 }
 
 /*
-  yylex remember the following states from the following yylex()
+  MYSQLlex remember the following states from the following MYSQLlex()
 
   - MY_LEX_EOQ			Found end of query
   - MY_LEX_OPERATOR_OR_IDENT	Last state was an ident, text or number
 				(which can't be followed by a signed number)
 */
 
-int yylex(void *arg, void *yythd)
+int MYSQLlex(void *arg, void *yythd)
 {
   reg1	uchar c;
   int	tokval, result_state;
diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index c98255e7ecc..66f097a101c 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -757,7 +757,7 @@ typedef struct st_lex
   const uchar *buf;		/* The beginning of string, used by SPs */
   const uchar *ptr,*tok_start,*tok_end,*end_of_query;
   
-  /* The values of tok_start/tok_end as they were one call of yylex before */
+  /* The values of tok_start/tok_end as they were one call of MYSQLlex before */
   const uchar *tok_start_prev, *tok_end_prev;
 
   char *length,*dec,*change,*name;
@@ -1119,7 +1119,7 @@ extern void lex_init(void);
 extern void lex_free(void);
 extern void lex_start(THD *thd, const uchar *buf, uint length);
 extern void lex_end(LEX *lex);
-extern int yylex(void *arg, void *yythd);
+extern int MYSQLlex(void *arg, void *yythd);
 
 extern pthread_key(LEX*,THR_LEX);
 
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 230fa624bce..112d2e3440a 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -4379,7 +4379,7 @@ end_with_restore_list:
       /*
         We must cleanup the unit and the lex here because
         sp_grant_privileges calls (indirectly) db_find_routine,
-        which in turn may call yyparse with THD::lex.
+        which in turn may call MYSQLparse with THD::lex.
         TODO: fix db_find_routine to use a temporary lex.
       */
       lex->unit.cleanup();
@@ -5818,7 +5818,7 @@ void mysql_parse(THD *thd, char *inBuf, uint length)
     sp_cache_flush_obsolete(&thd->sp_proc_cache);
     sp_cache_flush_obsolete(&thd->sp_func_cache);
     
-    if (!yyparse((void *)thd) && ! thd->is_fatal_error)
+    if (!MYSQLparse((void *)thd) && ! thd->is_fatal_error)
     {
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
       if (mqh_used && thd->user_connect &&
@@ -5910,7 +5910,7 @@ bool mysql_test_parse_for_slave(THD *thd, char *inBuf, uint length)
   DBUG_ENTER("mysql_test_parse_for_slave");
 
   mysql_init_query(thd, (uchar*) inBuf, length);
-  if (!yyparse((void*) thd) && ! thd->is_fatal_error &&
+  if (!MYSQLparse((void*) thd) && ! thd->is_fatal_error &&
       all_tables_not_ok(thd,(TABLE_LIST*) lex->select_lex.table_list.first))
     error= 1;                  /* Ignore question */
   thd->end_statement();
diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc
index a66b2bdb9b6..a0cfc5a7a9e 100644
--- a/sql/sql_prepare.cc
+++ b/sql/sql_prepare.cc
@@ -2758,7 +2758,7 @@ bool Prepared_statement::prepare(const char *packet, uint packet_len)
   lex_start(thd, (uchar*) thd->query, thd->query_length);
   lex->stmt_prepare_mode= TRUE;
 
-  error= yyparse((void *)thd) || thd->is_fatal_error ||
+  error= MYSQLparse((void *)thd) || thd->is_fatal_error ||
       thd->net.report_error || init_param_array(this);
   lex->safe_to_cache_query= FALSE;
   /*
diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc
index 4cd7c65bab0..f1ecae884d5 100644
--- a/sql/sql_trigger.cc
+++ b/sql/sql_trigger.cc
@@ -15,6 +15,7 @@
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA */
 
 
+#define MYSQL_LEX 1
 #include "mysql_priv.h"
 #include "sp_head.h"
 #include "sql_trigger.h"
@@ -928,7 +929,7 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
         lex_start(thd, (uchar*)trg_create_str->str, trg_create_str->length);
 
 	thd->spcont= 0;
-        if (yyparse((void *)thd) || thd->is_fatal_error)
+        if (MYSQLparse((void *)thd) || thd->is_fatal_error)
         {
           /*
             Free lex associated resources.
diff --git a/sql/sql_view.cc b/sql/sql_view.cc
index 6f642590993..1b5e91daf3e 100644
--- a/sql/sql_view.cc
+++ b/sql/sql_view.cc
@@ -15,6 +15,7 @@
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
 
+#define MYSQL_LEX 1
 #include "mysql_priv.h"
 #include "sql_select.h"
 #include "parse_file.h"
@@ -891,7 +892,7 @@ bool mysql_make_view(THD *thd, File_parser *parser, TABLE_LIST *table)
                                 MODE_IGNORE_SPACE | MODE_NO_BACKSLASH_ESCAPES);
     CHARSET_INFO *save_cs= thd->variables.character_set_client;
     thd->variables.character_set_client= system_charset_info;
-    res= yyparse((void *)thd);
+    res= MYSQLparse((void *)thd);
     thd->variables.character_set_client= save_cs;
     thd->variables.sql_mode= save_mode;
   }