diff --git a/effects/invert/data/invert.frag b/effects/invert/data/invert.frag
index 456c5414ff..753d3508a5 100644
--- a/effects/invert/data/invert.frag
+++ b/effects/invert/data/invert.frag
@@ -14,7 +14,7 @@ vec2 pix2tex( vec2 pix )
 void main()
 {
     vec4 tex = texture2D( winTexture, pix2tex( gl_TexCoord[0].st ));
-    tex = vec4( vec3( 1.0 ) - tex.rgb, tex.a * opacity );
+    tex = vec4(( vec3( 1.0 ) - tex.rgb / vec3( tex.a )) * vec3( tex.a * opacity ), tex.a * opacity );
     if( saturation != 1.0 )
         {
         vec3 desaturated = tex.rgb * vec3( 0.30, 0.59, 0.11 );