diff --git a/webrender/res/prim_shared.glsl b/webrender/res/prim_shared.glsl
index 193dcd79c7..7753298899 100644
--- a/webrender/res/prim_shared.glsl
+++ b/webrender/res/prim_shared.glsl
@@ -648,7 +648,7 @@ VertexInfo write_transform_vertex(RectWithSize local_segment_rect,
     // We also want that to apply to any interpolators. However, we
     // want a constant Z across the primitive, since we're using it
     // for draw ordering - so scale by the W coord to ensure this.
-    vec4 final_pos = vec4(world_pos.xy * uDevicePixelRatio + task_offset,
+    vec4 final_pos = vec4((device_pos + task_offset) * world_pos.w,
                           z * world_pos.w,
                           world_pos.w);
     gl_Position = uTransform * final_pos;
diff --git a/wrench/reftests/transforms/content-offset.png b/wrench/reftests/transforms/content-offset.png
new file mode 100644
index 0000000000..60eec2f6c3
Binary files /dev/null and b/wrench/reftests/transforms/content-offset.png differ
diff --git a/wrench/reftests/transforms/content-offset.yaml b/wrench/reftests/transforms/content-offset.yaml
new file mode 100644
index 0000000000..95c1e00e99
--- /dev/null
+++ b/wrench/reftests/transforms/content-offset.yaml
@@ -0,0 +1,16 @@
+---
+root:
+  items:
+    -
+      type: "stacking-context"
+      perspective: 1000
+      items:
+        -
+          type: "stacking-context"
+          transform: rotate-x(45) translate(100, 100, 0)
+          "transform-style": "preserve-3d"
+          items:
+              -
+                bounds: [0, 0, 200, 200]
+                type: rect
+                color: red
diff --git a/wrench/reftests/transforms/perspective.png b/wrench/reftests/transforms/perspective.png
index 65e0b29e74..70141c633b 100644
Binary files a/wrench/reftests/transforms/perspective.png and b/wrench/reftests/transforms/perspective.png differ
diff --git a/wrench/reftests/transforms/reftest.list b/wrench/reftests/transforms/reftest.list
index 91bfce9fa4..bebf785ca5 100644
--- a/wrench/reftests/transforms/reftest.list
+++ b/wrench/reftests/transforms/reftest.list
@@ -5,6 +5,8 @@
 # but fails when all the tests are run
 fuzzy(1,2) == rotated-image.yaml rotated-image.png
 == singular.yaml singular-ref.yaml
-fuzzy(1,82) == perspective.yaml perspective.png
+fuzzy(1,88) == perspective.yaml perspective.png
 == prim-suite.yaml prim-suite.png
 == segments-bug.yaml segments-bug-ref.yaml
+== content-offset.yaml content-offset.png
+