diff --git a/src/backend/wayland/wl_backend.c b/src/backend/wayland/wl_backend.c
index e3ff601..ea623b5 100644
--- a/src/backend/wayland/wl_backend.c
+++ b/src/backend/wayland/wl_backend.c
@@ -6223,8 +6223,8 @@ wl_pointer_query_full(WNativeWindow root,
     /* Phase 54: return tracked virtual pointer position. */
     (void)root;
     if (child_out) *child_out = WNATIVE_NONE;
-    *root_x = wl_state.pointer_x;
-    *root_y = wl_state.pointer_y;
+    if (root_x) *root_x = wl_state.pointer_x;
+    if (root_y) *root_y = wl_state.pointer_y;
     if (buttons_out) *buttons_out = 0;
     return wl_state.started ? 1 : 0;
 }