diff --git a/src/Shaders/Effects/IndexMap.gdshader b/src/Shaders/Effects/IndexMap.gdshader
index 46fecda00..96877b480 100644
--- a/src/Shaders/Effects/IndexMap.gdshader
+++ b/src/Shaders/Effects/IndexMap.gdshader
@@ -3,7 +3,7 @@ shader_type canvas_item;
 render_mode unshaded;
 
 uniform sampler2D map_texture : filter_nearest;  // The map texture
-uniform bool alpha = false;
+uniform bool include_alpha = false;
 
 // (begin DESCRIPTION)
 // The Red and Green values (0-255) of tool color will be treated as an x and y position
@@ -16,7 +16,7 @@ void fragment() {
 	vec2 lookup_uv = vec2(round(col.x * 255.0)/(map_size.x), round(col.y * 255.0)/(map_size.y));
 	vec4 index_color = texture(map_texture, lookup_uv);
 	COLOR.rgb = index_color.rgb;
-	if (alpha) {
+	if (include_alpha) {
 		COLOR.a = index_color.a;
 	}
 }