diff --git a/Xi/xiproperty.c b/Xi/xiproperty.c
index b9f53f7dc..17835e2cd 100644
--- a/Xi/xiproperty.c
+++ b/Xi/xiproperty.c
@@ -701,7 +701,7 @@ XIDeleteDeviceProperty (DeviceIntPtr device, Atom property, Bool fromClient)
 int
 XIChangeDeviceProperty (DeviceIntPtr dev, Atom property, Atom type,
                         int format, int mode, unsigned long len,
-                        pointer value, Bool sendevent)
+                        const pointer value, Bool sendevent)
 {
     XIPropertyPtr               prop;
     int                         size_in_bytes;
diff --git a/include/exevents.h b/include/exevents.h
index dc594304f..2b226986b 100644
--- a/include/exevents.h
+++ b/include/exevents.h
@@ -69,7 +69,7 @@ extern _X_EXPORT int XIChangeDeviceProperty(
         int                     /* format*/,
         int                     /* mode*/,
         unsigned long           /* len*/,
-        pointer                 /* value*/,
+        const pointer           /* value*/,
         Bool                    /* sendevent*/
         );