Index: uspace/lib/gui/window.c
===================================================================
--- uspace/lib/gui/window.c	(revision d65be39ddf1f6260963a5f1157e7baedaad1f17c)
+++ uspace/lib/gui/window.c	(revision 7856d096ccea34cfe2f6cdd077ec231776bed992)
@@ -529,5 +529,5 @@
 }
 
-window_t *window_open(char *winreg, bool is_main, bool is_decorated, 
+window_t *window_open(const char *winreg, bool is_main, bool is_decorated,
     const char *caption, sysarg_t x_offset, sysarg_t y_offset)
 {
Index: uspace/lib/gui/window.h
===================================================================
--- uspace/lib/gui/window.h	(revision d65be39ddf1f6260963a5f1157e7baedaad1f17c)
+++ uspace/lib/gui/window.h	(revision 7856d096ccea34cfe2f6cdd077ec231776bed992)
@@ -66,5 +66,6 @@
  * If the window is declared as main, its closure causes termination of the
  * whole application. Note that opened window does not have any surface yet. */
-extern window_t *window_open(char *, bool, bool, const char *, sysarg_t, sysarg_t);
+extern window_t *window_open(const char *, bool, bool, const char *, sysarg_t,
+    sysarg_t);
 
 /**