diff --git a/src/Three.Legacy.js b/src/Three.Legacy.js
index a4dd3e8634eceecb16e0b77826ff3d13c61b24f4..c67971215502de201351d6d4cf3656b958f2c4a9 100644
--- a/src/Three.Legacy.js
+++ b/src/Three.Legacy.js
@@ -1047,7 +1047,7 @@ Object.defineProperties( Material.prototype, {
 		set: function ( value ) {
 
 			console.warn( 'THREE.' + this.type + ': .shading has been removed. Use the boolean .flatShading instead.' );
-			this.flatShading = value === FlatShading;
+			this.flatShading = ( value === FlatShading );
 
 		}
 	}