diff --git a/Changes.md b/Changes.md
index 947bbae98c3..df0a88de5d2 100644
--- a/Changes.md
+++ b/Changes.md
@@ -1,6 +1,10 @@
 1.2.10.x (relative to 1.2.10.1)
 ========
 
+Fixes
+-----
+
+- Arnold : Fixed screen window export for Lentil cameras.
 
 1.2.10.1 (relative to 1.2.10.0)
 ========
diff --git a/src/IECoreArnold/CameraAlgo.cpp b/src/IECoreArnold/CameraAlgo.cpp
index 6289c2cca0b..5a1f4828cf4 100644
--- a/src/IECoreArnold/CameraAlgo.cpp
+++ b/src/IECoreArnold/CameraAlgo.cpp
@@ -190,7 +190,7 @@ Imath::Box2f screenWindow( const IECoreScene::Camera *camera )
 {
 	Imath::Box2f result = camera->frustum();
 
-	if( camera->getProjection() == "perspective" )
+	if( camera->getProjection() == "perspective" || camera->getProjection() == "lentil_camera" )
 	{
 		// Normalise so that Arnold's NDC space goes from 0-1 across the aperture.
 		// This is helpful when using Arnold `uv_remap` shaders.