diff --git a/Sources/Engine/Base/Parser.cpp b/Sources/Engine/Base/Parser.cpp
index 7f30df6..3e9d3ce 100644
--- a/Sources/Engine/Base/Parser.cpp
+++ b/Sources/Engine/Base/Parser.cpp
@@ -156,7 +156,7 @@
 
 #define YYERROR_VERBOSE 1
 // if error occurs in parsing
-void yyerror(char *str)
+void yyerror(const char *str)
 {
   // just report the string
   _pShell->ErrorF("%s", str);
diff --git a/Sources/Engine/Base/Parser.y b/Sources/Engine/Base/Parser.y
index f15ee68..c09823f 100644
--- a/Sources/Engine/Base/Parser.y
+++ b/Sources/Engine/Base/Parser.y
@@ -18,7 +18,7 @@
 
 #define YYERROR_VERBOSE 1
 // if error occurs in parsing
-void yyerror(char *str)
+void yyerror(const char *str)
 {
   // just report the string
   _pShell->ErrorF("%s", str);
diff --git a/Sources/Engine/Base/ParsingSymbols.h b/Sources/Engine/Base/ParsingSymbols.h
index 341248e..98f2597 100644
--- a/Sources/Engine/Base/ParsingSymbols.h
+++ b/Sources/Engine/Base/ParsingSymbols.h
@@ -12,7 +12,7 @@
 #define yyparse yyparse_engine_base_parser
 #define yyerror yyerror_engine_base_parser
 
-extern void yyerror(char *s);
+extern void yyerror(const char *s);
 extern int yyparse(void);
 
 typedef struct yy_buffer_state *YY_BUFFER_STATE;
diff --git a/Sources/Engine/Ska/ParsingSmbs.h b/Sources/Engine/Ska/ParsingSmbs.h
index bdfebc3..400485f 100644
--- a/Sources/Engine/Ska/ParsingSmbs.h
+++ b/Sources/Engine/Ska/ParsingSmbs.h
@@ -2,7 +2,7 @@
 
 // needed for parser and scanner
 extern int engine_ska_yylex(void);
-extern void engine_ska_yyerror(char *s);
+extern void engine_ska_yyerror(const char *s);
 extern int engine_ska_yyparse(void);
 extern void engine_ska_yyrestart(FILE *f);
 
diff --git a/Sources/Engine/Ska/smcPars.y b/Sources/Engine/Ska/smcPars.y
index b11a3a0..0877b4e 100644
--- a/Sources/Engine/Ska/smcPars.y
+++ b/Sources/Engine/Ska/smcPars.y
@@ -26,7 +26,7 @@ BOOL bOffsetAllreadySet = FALSE;
 #define YYERROR_VERBOSE 0
 
 // if error occurs in parsing
-void yyerror(char *str)
+void yyerror(const char *str)
 {
   //_pShell->ErrorF("%s", str);
   _pShell->ErrorF("File '%s'\n %s (line %d)",SMCGetBufferName(), str, SMCGetBufferLineNumber());