diff --git a/ide/buildlazdialog.pas b/ide/buildlazdialog.pas
index 7bb6098054..06954a93b7 100644
--- a/ide/buildlazdialog.pas
+++ b/ide/buildlazdialog.pas
@@ -951,7 +951,13 @@ begin
     fs:=TFileStreamUTF8.Create(Filename,fmCreate);
     try
       if fExtraOptions<>'' then begin
-        OptionsAsText:=BreakExtraOptions;
+        {$IFDEF MSWindows}
+        // Under Windows FPC expects console codepage for command line params
+        // and system codepage in config files
+        OptionsAsText:=UTF8ToWinCP(BreakExtraOptions);
+        {$ELSE}
+        OptionsAsText:=UTF8ToSys(BreakExtraOptions);
+        {$ENDIF}
         fs.Write(OptionsAsText[1],length(OptionsAsText));
       end;
     finally