diff --git a/libs/gui/Surface.cpp b/libs/gui/Surface.cpp
index 44d9b4b..812bd6a 100644
--- a/libs/gui/Surface.cpp
+++ b/libs/gui/Surface.cpp
@@ -536,9 +536,9 @@
     return self->queueBuffer(buffer);
 }
 
-int Surface::query(ANativeWindow* window, 
+int Surface::query(const ANativeWindow* window,
         int what, int* value) {
-    Surface* self = getSelf(window);
+    const Surface* self = getSelf(window);
     return self->query(what, value);
 }
 
@@ -697,7 +697,7 @@
     return err;
 }
 
-int Surface::query(int what, int* value)
+int Surface::query(int what, int* value) const
 {
     switch (what) {
     case NATIVE_WINDOW_WIDTH: