diff --git a/hw/xfree86/common/xf86Opt.h b/hw/xfree86/common/xf86Opt.h
index 0d808de14..c3ba2d75c 100644
--- a/hw/xfree86/common/xf86Opt.h
+++ b/hw/xfree86/common/xf86Opt.h
@@ -85,7 +85,7 @@ extern _X_EXPORT int xf86CheckIntOption(XF86OptionPtr optlist, const char *name,
 extern _X_EXPORT double xf86CheckRealOption(XF86OptionPtr optlist,
                                             const char *name, double deflt);
 extern _X_EXPORT char *xf86CheckStrOption(XF86OptionPtr optlist,
-                                          const char *name, char *deflt);
+                                          const char *name, const char *deflt);
 extern _X_EXPORT int xf86CheckBoolOption(XF86OptionPtr list, const char *name,
                                          int deflt);
 extern _X_EXPORT double xf86CheckPercentOption(XF86OptionPtr list,
diff --git a/hw/xfree86/common/xf86Option.c b/hw/xfree86/common/xf86Option.c
index 7cc744029..c2ec79a53 100644
--- a/hw/xfree86/common/xf86Option.c
+++ b/hw/xfree86/common/xf86Option.c
@@ -276,7 +276,7 @@ xf86CheckRealOption(XF86OptionPtr optlist, const char *name, double deflt)
 }
 
 char *
-xf86CheckStrOption(XF86OptionPtr optlist, const char *name, char *deflt)
+xf86CheckStrOption(XF86OptionPtr optlist, const char *name, const char *deflt)
 {
     return LookupStrOption(optlist, name, deflt, FALSE);
 }