diff --git a/src/gba/renderers/gl.c b/src/gba/renderers/gl.c
index 9d7ccafa7..b6ffa2aac 100644
--- a/src/gba/renderers/gl.c
+++ b/src/gba/renderers/gl.c
@@ -664,10 +664,12 @@ static const char* const _finalize =
 	"	if (((topFlags.y & 13) == 5 || topFlags.w > 0) && (bottomFlags.y & 2) == 2) {\n"
 	"		topPixel.rgb *= float(topFlags.z) / 16.;\n"
 	"		topPixel.rgb += bottomPixel.rgb * float(windowFlags.y) / 16.;\n"
-	"	} else if ((topFlags.y & 13) == 9) {\n"
-	"		topPixel.rgb += (1. - topPixel.rgb) * float(windowFlags.z) / 16.;\n"
-	"	} else if ((topFlags.y & 13) == 13) {\n"
-	"		topPixel.rgb -= topPixel.rgb * float(windowFlags.z) / 16.;\n"
+	"	} else if (topFlags.w == 0) { \n"
+	"		if ((topFlags.y & 13) == 9) {\n"
+	"			topPixel.rgb += (1. - topPixel.rgb) * float(windowFlags.z) / 16.;\n"
+	"		} else if ((topFlags.y & 13) == 13) {\n"
+	"			topPixel.rgb -= topPixel.rgb * float(windowFlags.z) / 16.;\n"
+	"		}\n"
 	"	}\n"
 	"	color = topPixel;\n"
 	"}";