diff --git a/src/conio/ciolib.h b/src/conio/ciolib.h
index 250f4e99411d8c39776f6c8aa4750b31da69b49d..f69da8a27ec22d2a6f4e1a6277472b9fd826ebc3 100644
--- a/src/conio/ciolib.h
+++ b/src/conio/ciolib.h
@@ -395,7 +395,7 @@ CIOLIBEXPORTVAR int directvideo;
 CIOLIBEXPORTVAR int hold_update;
 CIOLIBEXPORTVAR int puttext_can_move;
 CIOLIBEXPORTVAR int ciolib_reaper;
-CIOLIBEXPORTVAR char *ciolib_appname;
+CIOLIBEXPORTVAR const char *ciolib_appname;
 CIOLIBEXPORTVAR int ciolib_initial_window_height;
 CIOLIBEXPORTVAR int ciolib_initial_window_width;