diff --git a/shaders.cpp b/shaders.cpp
index 59316e09..ab705ff0 100644
--- a/shaders.cpp
+++ b/shaders.cpp
@@ -520,7 +520,9 @@ shared_ptr<glhr::GLprogram> write_shader(flagtype shader_flags) {
       shader_flags |= SF_ORIENT;
       }
     else if((shader_flags & SF_PERS3) && stereo_alpha && !vrhr::rendering_eye()) {
+      vmain += "t = uPP * t;", vsh += "uniform mediump mat4 uPP;";
       vmain += stereo_shader();
+      shader_flags |= SF_ORIENT;
       }
       
     vmain += "gl_Position = uP * t;\n";