diff --git a/piet-scene/src/geometry.rs b/piet-scene/src/geometry.rs
index 1ea8f33..2df7f83 100644
--- a/piet-scene/src/geometry.rs
+++ b/piet-scene/src/geometry.rs
@@ -61,7 +61,7 @@ impl From<(f32, f32)> for Point {
 }
 
 /// Affine transformation matrix.
-#[derive(Copy, Clone, Debug, Pod, Zeroable)]
+#[derive(Copy, Clone, PartialEq, Debug, Pod, Zeroable)]
 #[repr(C)]
 pub struct Affine {
     pub xx: f32,
diff --git a/piet-scene/src/scene/builder.rs b/piet-scene/src/scene/builder.rs
index a890239..5394f88 100644
--- a/piet-scene/src/scene/builder.rs
+++ b/piet-scene/src/scene/builder.rs
@@ -160,11 +160,13 @@ impl<'a> Builder<'a> {
     pub fn append(&mut self, fragment: &Fragment, transform: Option<Affine>) {
         let drawdata_base = self.scene.drawdata_stream.len();
         let mut cur_transform = self.scene.transform_stream.last().copied();
-        if cur_transform.is_none() {
-            if let Some(transform) = transform {
-                self.encode_transform(transform);
+        if let Some(transform) = transform {
+            if cur_transform.is_none() {
                 cur_transform = Some(Affine::IDENTITY);
             }
+            self.encode_transform(transform);
+        } else if cur_transform != Some(Affine::IDENTITY) {
+            self.encode_transform(Affine::IDENTITY);
         }
         self.scene.append(&fragment.data, &transform);
         match &mut self.resources {