diff --git a/include/common.h b/include/common.h
index 372cf07..8524162 100644
--- a/include/common.h
+++ b/include/common.h
@@ -1,5 +1,7 @@
 #ifndef COMMON_H
 #define COMMON_H
+//#include <algorithm>
+#include <cctype>
 #include <iostream>
 #include <memory>
 #include <set>
@@ -314,4 +316,8 @@ inline bool str2uint(const char* str, uint64_t* res)
 inline bool str2double(const std::string& str, double* res) {return str2double(str.c_str(),res);}
 inline bool str2int(const std::string& str, int64_t* res) {return str2int(str.c_str(),res);}
 inline bool str2uint(const std::string& str, int64_t* res) {return str2uint(str.c_str(),res);}
+
+inline void tolower(std::string& str) {for(auto& p: str) p=tolower(p);}
+inline void tolower(std::string* str) {for(auto& p:*str) p=tolower(p);}
+inline void tolower(char* str) {for(*str=tolower(*str);'\0'!=*str++;*str=tolower(*str));}
 #endif
diff --git a/src/parser/grammatical.y b/src/parser/grammatical.y
index 2ade5c6..0f0aedc 100644
--- a/src/parser/grammatical.y
+++ b/src/parser/grammatical.y
@@ -14,7 +14,6 @@
 
 %{
 #include <inttypes.h>
-#include <algorithm>
 #include "parser.h"
 #include "object.h"
 #include "globals.h"
@@ -104,7 +103,7 @@ line:
         NAME ASSIGN object ENDL                 {COUT(DEBUG)<<" NAME ASSIGN object ENDL\n"; if(G_vars.count(*$1)!=0) delete G_vars[*$1]; G_vars[*$1]=$3; delete $1;}
         | NAME ASSIGN list ENDL                 {COUT(DEBUG)<<" NAME ASSIGN list ENDL\n"; if(G_vars.count(*$1)!=0) delete G_vars[*$1]; G_vars[*$1]=$3; delete $1;}
         | NAME OBRACE list CBRACE ENDL          {COUT(DEBUG)<<" NAME OBRACE list CBRACE ENDL\n";
-                                                 transform($1->begin(),$1->end(),$1->begin(),::tolower);
+                                                 tolower($1);
                                                  ObjectList* ol=dynamic_cast<ObjectList*>($3);
                                                  if(*$1=="save") G_tosave.push_back(ol);
                                                  else if(*$1=="print") G_toprint.push_back(ol);
@@ -117,7 +116,7 @@ line:
                                                  }
                                                  delete $1;}
         | NAME OBRACE object CBRACE ENDL        {COUT(DEBUG)<<" NAME OBRACE object CBRACE ENDL\n";
-                                                 transform($1->begin(),$1->end(),$1->begin(),::tolower);
+                                                 tolower($1);
                                                  ObjectList* ol=new ObjectList($3);
                                                  if(*$1=="save") G_tosave.push_back(ol);
                                                  else if(*$1=="print") G_toprint.push_back(ol);
diff --git a/src/parser/lexical.l b/src/parser/lexical.l
index 9c8cb07..33a90b9 100644
--- a/src/parser/lexical.l
+++ b/src/parser/lexical.l
@@ -14,7 +14,6 @@
 %x PREPROC
 
 %{
-#include <algorithm>
 #include "common.h"
 #include "parser.h"
 // flex use register keyword, but it deprecated in C++11.
@@ -44,7 +43,7 @@ std::string str;
 <PARSE,INITIAL>@[Ii][Nn][Cc][Ll][Uu][Dd][Ee][ \t]*\" yy_push_state(INCLUDE,yyscanner); str.erase(); yynextsym;
 @                                               BEGIN(PREPROC); yynextsym;
 <PREPROC>[a-zA-Z]*                              {
-                                                 yynextsym; str=yytext; transform(str.begin(),str.end(),str.begin(),::tolower);
+                                                 yynextsym; str=yytext; tolower(str);
                                                  if("use"==str) return DIR_USE;
                                                  if("includepath"==str) return DIR_INCLUDEPATH;
                                                  if("modulepath"==str) return DIR_MODULEPATH;