diff --git a/Common/GPU/ShaderWriter.h b/Common/GPU/ShaderWriter.h
index 6eb42719f0..610a7fe0ec 100644
--- a/Common/GPU/ShaderWriter.h
+++ b/Common/GPU/ShaderWriter.h
@@ -33,6 +33,7 @@ struct VaryingDef {
 enum class ShaderWriterFlags {
 	NONE = 0,
 	FS_WRITE_DEPTH = 1,
+	FS_AUTO_STEREO = 2,
 };
 ENUM_CLASS_BITOPS(ShaderWriterFlags);