diff --git a/webrender/src/border.rs b/webrender/src/border.rs
index a249148f9d..1e01e9d20e 100644
--- a/webrender/src/border.rs
+++ b/webrender/src/border.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use api::{BorderRadius, BorderSide, BorderStyle, BorderWidths, ColorF, LayerPoint};
+use api::{BorderRadius, BorderSide, BorderStyle, BorderWidths, ClipMode, ColorF, LayerPoint};
 use api::{LayerPrimitiveInfo, LayerRect, LayerSize, NormalBorder, RepeatMode, TexelRect};
 use clip::ClipSource;
 use ellipse::Ellipse;
@@ -373,6 +373,63 @@ impl<'a> DisplayListFlattener<'a> {
         let top = &border.top;
         let bottom = &border.bottom;
 
+        let constant_color = left.color;
+        let is_simple_border = [left, top, right, bottom].iter().all(|edge| {
+            edge.style == BorderStyle::Solid &&
+            edge.color == constant_color
+        });
+
+        if is_simple_border {
+            let extra_clips = vec![
+                ClipSource::new_rounded_rect(
+                    info.rect,
+                    border.radius,
+                    ClipMode::Clip,
+                ),
+                ClipSource::new_rounded_rect(
+                    LayerRect::new(
+                        LayerPoint::new(
+                            info.rect.origin.x + widths.left,
+                            info.rect.origin.y + widths.top,
+                        ),
+                        LayerSize::new(
+                            info.rect.size.width - widths.left - widths.right,
+                            info.rect.size.height - widths.top - widths.bottom,
+                        ),
+                    ),
+                    BorderRadius {
+                        top_left: LayerSize::new(
+                            (border.radius.top_left.width - widths.left).max(0.0),
+                            (border.radius.top_left.height - widths.top).max(0.0),
+                        ),
+                        top_right: LayerSize::new(
+                            (border.radius.top_right.width - widths.right).max(0.0),
+                            (border.radius.top_right.height - widths.top).max(0.0),
+                        ),
+                        bottom_left: LayerSize::new(
+                            (border.radius.bottom_left.width - widths.left).max(0.0),
+                            (border.radius.bottom_left.height - widths.bottom).max(0.0),
+                        ),
+                        bottom_right: LayerSize::new(
+                            (border.radius.bottom_right.width - widths.right).max(0.0),
+                            (border.radius.bottom_right.height - widths.bottom).max(0.0),
+                        ),
+                    },
+                    ClipMode::ClipOut,
+                ),
+            ];
+
+            self.add_solid_rectangle(
+                clip_and_scroll,
+                info,
+                border.top.color,
+                None,
+                extra_clips,
+            );
+
+            return;
+        }
+
         let corners = [
             border.get_corner(
                 left,
@@ -465,6 +522,7 @@ impl<'a> DisplayListFlattener<'a> {
                     info,
                     border.top.color,
                     Some(descriptor),
+                    Vec::new(),
                 );
             }
 
@@ -481,6 +539,7 @@ impl<'a> DisplayListFlattener<'a> {
                     info,
                     border.left.color,
                     Some(descriptor),
+                    Vec::new(),
                 );
             }
 
@@ -497,6 +556,7 @@ impl<'a> DisplayListFlattener<'a> {
                     info,
                     border.right.color,
                     Some(descriptor),
+                    Vec::new(),
                 );
             }
 
@@ -515,6 +575,7 @@ impl<'a> DisplayListFlattener<'a> {
                     info,
                     border.bottom.color,
                     Some(descriptor),
+                    Vec::new(),
                 );
             }
         } else {
diff --git a/webrender/src/display_list_flattener.rs b/webrender/src/display_list_flattener.rs
index ed4d110c3f..9f8630b1f8 100644
--- a/webrender/src/display_list_flattener.rs
+++ b/webrender/src/display_list_flattener.rs
@@ -349,6 +349,7 @@ impl<'a> DisplayListFlattener<'a> {
                         &info,
                         bg_color,
                         None,
+                        Vec::new(),
                     );
                 }
             }
@@ -700,6 +701,7 @@ impl<'a> DisplayListFlattener<'a> {
                     &prim_info,
                     info.color,
                     None,
+                    Vec::new(),
                 );
             }
             SpecificDisplayItem::ClearRectangle => {
@@ -1512,6 +1514,7 @@ impl<'a> DisplayListFlattener<'a> {
         info: &LayerPrimitiveInfo,
         color: ColorF,
         segments: Option<BrushSegmentDescriptor>,
+        extra_clips: Vec<ClipSource>,
     ) {
         if color.a == 0.0 {
             // Don't add transparent rectangles to the draw list, but do consider them for hit
@@ -1530,7 +1533,7 @@ impl<'a> DisplayListFlattener<'a> {
         self.add_primitive(
             clip_and_scroll,
             info,
-            Vec::new(),
+            extra_clips,
             PrimitiveContainer::Brush(prim),
         );
     }
diff --git a/wrench/reftests/border/border-clamp-corner-radius-ref.png b/wrench/reftests/border/border-clamp-corner-radius-ref.png
deleted file mode 100644
index 69c73c92b2..0000000000
Binary files a/wrench/reftests/border/border-clamp-corner-radius-ref.png and /dev/null differ
diff --git a/wrench/reftests/border/border-clamp-corner-radius.png b/wrench/reftests/border/border-clamp-corner-radius.png
new file mode 100644
index 0000000000..bdeda43864
Binary files /dev/null and b/wrench/reftests/border/border-clamp-corner-radius.png differ
diff --git a/wrench/reftests/border/border-radii.png b/wrench/reftests/border/border-radii.png
index 87d5b674fd..5e72e1646a 100644
Binary files a/wrench/reftests/border/border-radii.png and b/wrench/reftests/border/border-radii.png differ
diff --git a/wrench/reftests/border/reftest.list b/wrench/reftests/border/reftest.list
index 485ea50ebd..c6de4090f9 100644
--- a/wrench/reftests/border/reftest.list
+++ b/wrench/reftests/border/reftest.list
@@ -1,4 +1,4 @@
-== border-clamp-corner-radius.yaml border-clamp-corner-radius-ref.png
+== border-clamp-corner-radius.yaml border-clamp-corner-radius.png
 == border-gradient-simple.yaml border-gradient-simple-ref.yaml
 == border-radial-gradient-simple.yaml border-radial-gradient-simple-ref.yaml
 == border-radii.yaml border-radii.png
diff --git a/wrench/reftests/clip/border-with-rounded-clip-ref.png b/wrench/reftests/clip/border-with-rounded-clip-ref.png
deleted file mode 100644
index dc775d6e44..0000000000
Binary files a/wrench/reftests/clip/border-with-rounded-clip-ref.png and /dev/null differ
diff --git a/wrench/reftests/clip/border-with-rounded-clip.png b/wrench/reftests/clip/border-with-rounded-clip.png
new file mode 100644
index 0000000000..676f206991
Binary files /dev/null and b/wrench/reftests/clip/border-with-rounded-clip.png differ
diff --git a/wrench/reftests/clip/reftest.list b/wrench/reftests/clip/reftest.list
index 942fc7c256..4250f1ca17 100644
--- a/wrench/reftests/clip/reftest.list
+++ b/wrench/reftests/clip/reftest.list
@@ -1,4 +1,4 @@
-== border-with-rounded-clip.yaml border-with-rounded-clip-ref.png
+== border-with-rounded-clip.yaml border-with-rounded-clip.png
 == clip-mode.yaml clip-mode.png
 == clip-ellipse.yaml clip-ellipse.png
 == clip-45-degree-rotation.yaml clip-45-degree-rotation-ref.png
diff --git a/wrench/reftests/mask/rounded-corners.png b/wrench/reftests/mask/rounded-corners.png
index b55f7baba7..3acf447cd1 100644
Binary files a/wrench/reftests/mask/rounded-corners.png and b/wrench/reftests/mask/rounded-corners.png differ
diff --git a/wrench/reftests/transforms/rotated-image.png b/wrench/reftests/transforms/rotated-image.png
index f19eaa04c9..8e58ae42ad 100644
Binary files a/wrench/reftests/transforms/rotated-image.png and b/wrench/reftests/transforms/rotated-image.png differ