diff --git a/include/CColor.hpp b/include/CColor.hpp
index cb52926..c9b77b1 100644
--- a/include/CColor.hpp
+++ b/include/CColor.hpp
@@ -296,7 +296,7 @@ public:
     void toHSL(float& h, float& s, float& l);
 
     CColor toGrayscale()
-    { return {Math::sqrtF((r * r + g * g + b * b) / 3)}; }
+    { return {Math::sqrtF((r * r + g * g + b * b) / 3), a}; }
 };
 
 static inline CColor operator+(float lhs, const CColor& rhs)