diff --git a/Assets/Shaders/Chapter12/Chapter12-EdgeDetection.shader b/Assets/Shaders/Chapter12/Chapter12-EdgeDetection.shader
index dc919dee..651ec196 100644
--- a/Assets/Shaders/Chapter12/Chapter12-EdgeDetection.shader
+++ b/Assets/Shaders/Chapter12/Chapter12-EdgeDetection.shader
@@ -51,10 +51,10 @@ Shader "Unity Shaders Book/Chapter 12/Edge Detection" {
 			}
 			
 			half Sobel(v2f i) {
-				const half Gx[9] = {-1,  0,  1,
+				half Gx[9] = {-1,  0,  1,
 										-2,  0,  2,
 										-1,  0,  1};
-				const half Gy[9] = {-1, -2, -1,
+				half Gy[9] = {-1, -2, -1,
 										0,  0,  0,
 										1,  2,  1};