diff --git a/server/mapping.c b/server/mapping.c
index dc0690c68da..a273ed513df 100644
--- a/server/mapping.c
+++ b/server/mapping.c
@@ -149,6 +149,12 @@ static void mapping_destroy( struct object *obj )
     if (mapping->file) release_object( mapping->file );
 }
 
+int get_page_size(void)
+{
+    if (!page_mask) init_page_size();
+    return page_mask + 1;
+}
+
 /* create a file mapping */
 DECL_HANDLER(create_mapping)
 {
diff --git a/server/object.h b/server/object.h
index c6789334d2b..00cbd956671 100644
--- a/server/object.h
+++ b/server/object.h
@@ -159,6 +159,10 @@ extern int free_console( struct process *process );
 extern int debugger_attach( struct process *process, struct thread *debugger );
 extern void debug_exit_thread( struct thread *thread, int exit_code );
 
+/* mapping functions */
+
+extern int get_page_size(void);
+
 extern int debug_level;
 
 #endif  /* __WINE_SERVER_OBJECT_H */