diff --git a/intern/cycles/blender/blender_sync.cpp b/intern/cycles/blender/blender_sync.cpp
index 24a561116ec..c63f72c68c6 100644
--- a/intern/cycles/blender/blender_sync.cpp
+++ b/intern/cycles/blender/blender_sync.cpp
@@ -397,7 +397,15 @@ SessionParams BlenderSync::get_session_params(BL::RenderEngine b_engine, BL::Use
 	}
 	else
 		params.progressive = true;
-	
+
+	/* shading system - scene level needs full refresh */
+	int shadingsystem = RNA_enum_get(&cscene, "shading_system");
+
+	if(shadingsystem == 0)
+		params.shadingsystem = SessionParams::SVM;
+	else if(shadingsystem == 1)
+		params.shadingsystem = SessionParams::OSL;
+
 	return params;
 }
 
diff --git a/intern/cycles/render/session.h b/intern/cycles/render/session.h
index a7d2bd56fd1..8941c6ac459 100644
--- a/intern/cycles/render/session.h
+++ b/intern/cycles/render/session.h
@@ -57,6 +57,8 @@ public:
 	double reset_timeout;
 	double text_timeout;
 
+	enum { OSL, SVM } shadingsystem;
+
 	SessionParams()
 	{
 		background = false;
@@ -73,6 +75,8 @@ public:
 		cancel_timeout = 0.1;
 		reset_timeout = 0.1;
 		text_timeout = 1.0;
+
+		shadingsystem = SVM;
 	}
 
 	bool modified(const SessionParams& params)
@@ -89,7 +93,8 @@ public:
 		&& threads == params.threads
 		&& cancel_timeout == params.cancel_timeout
 		&& reset_timeout == params.reset_timeout
-		&& text_timeout == params.text_timeout); }
+		&& text_timeout == params.text_timeout
+		&& shadingsystem == params.shadingsystem); }
 
 };