diff --git a/core/fxcrt/fx_coordinates.h b/core/fxcrt/fx_coordinates.h
index e458380..4a7d33c 100644
--- a/core/fxcrt/fx_coordinates.h
+++ b/core/fxcrt/fx_coordinates.h
@@ -339,6 +339,8 @@
   // NOLINTNEXTLINE(runtime/explicit)
   CFX_RectF(const CFX_RectF& other) = default;
 
+  CFX_RectF& operator=(const CFX_RectF& other) = default;
+
   CFX_RectF& operator+=(const PointType& p) {
     left += p.x;
     top += p.y;