diff --git a/libs/input/PointerController.h b/libs/input/PointerController.h
index c7e772d..01748a8 100644
--- a/libs/input/PointerController.h
+++ b/libs/input/PointerController.h
@@ -70,7 +70,7 @@
     void setInactivityTimeout(InactivityTimeout inactivityTimeout);
     void doInactivityTimeout();
     void reloadPointerResources();
-    void onDisplayViewportsUpdated(std::vector<DisplayViewport>& viewports);
+    void onDisplayViewportsUpdated(const std::vector<DisplayViewport>& viewports);
 
     void onDisplayInfosChangedLocked(const std::vector<gui::DisplayInfo>& displayInfos)
             REQUIRES(getLock());