diff --git a/webrender/res/ps_border_corner.glsl b/webrender/res/ps_border_corner.glsl
index f78863cd4e..9933dd4f4f 100644
--- a/webrender/res/ps_border_corner.glsl
+++ b/webrender/res/ps_border_corner.glsl
@@ -19,6 +19,8 @@ flat varying vec2 vClipSign;
 flat varying vec4 vEdgeDistance;
 flat varying float vSDFSelect;
 
+flat varying float vIsBorderRadiusLessThanBorderWidth;
+
 // Border style
 flat varying float vAlphaSelect;
 
@@ -180,6 +182,8 @@ void main(void) {
             edge_distances = vec4(p0 + adjusted_widths.xy,
                                   p0 + inv_adjusted_widths.xy);
             color_delta = vec2(1.0);
+            vIsBorderRadiusLessThanBorderWidth = any(lessThan(border.radii[0].xy,
+                                                              border.widths.xy)) ? 1.0 : 0.0;
             break;
         }
         case 1: {
@@ -204,6 +208,8 @@ void main(void) {
                                   p1.x - border.widths.z + adjusted_widths.z,
                                   p0.y + inv_adjusted_widths.y);
             color_delta = vec2(1.0, -1.0);
+            vIsBorderRadiusLessThanBorderWidth = any(lessThan(border.radii[0].zw,
+                                                              border.widths.zy)) ? 1.0 : 0.0;
             break;
         }
         case 2: {
@@ -228,6 +234,8 @@ void main(void) {
                                   p1.x - border.widths.z + adjusted_widths.z,
                                   p1.y - border.widths.w + adjusted_widths.w);
             color_delta = vec2(-1.0);
+            vIsBorderRadiusLessThanBorderWidth = any(lessThan(border.radii[1].xy,
+                                                              border.widths.zw)) ? 1.0 : 0.0;
             break;
         }
         case 3: {
@@ -252,6 +260,8 @@ void main(void) {
                                   p0.x + inv_adjusted_widths.x,
                                   p1.y - border.widths.w + adjusted_widths.w);
             color_delta = vec2(-1.0, 1.0);
+            vIsBorderRadiusLessThanBorderWidth = any(lessThan(border.radii[1].zw,
+                                                              border.widths.xw)) ? 1.0 : 0.0;
             break;
         }
     }
@@ -332,7 +342,8 @@ void main(void) {
     // Only apply the clip AA if inside the clip region. This is
     // necessary for correctness when the border width is greater
     // than the border radius.
-    if (all(lessThan(local_pos * vClipSign, vClipCenter * vClipSign))) {
+    if (vIsBorderRadiusLessThanBorderWidth == 0.0 ||
+        all(lessThan(local_pos * vClipSign, vClipCenter * vClipSign))) {
         vec2 p = local_pos - vClipCenter;
 
         // The coordinate system is snapped to pixel boundaries. To sample the distance,
diff --git a/wrench/reftests/border/border-no-bogus-line-ref.png b/wrench/reftests/border/border-no-bogus-line-ref.png
new file mode 100644
index 0000000000..52344a03fe
Binary files /dev/null and b/wrench/reftests/border/border-no-bogus-line-ref.png differ
diff --git a/wrench/reftests/border/border-no-bogus-line.yaml b/wrench/reftests/border/border-no-bogus-line.yaml
new file mode 100644
index 0000000000..a030211da9
--- /dev/null
+++ b/wrench/reftests/border/border-no-bogus-line.yaml
@@ -0,0 +1,13 @@
+---
+root:
+  items:
+    - type: stacking-context
+      bounds: [0, 0, 100, 100]
+      items:
+        - type: border
+          bounds: [ 10, 10, 90, 80 ]
+          width: 3
+          border-type: normal
+          style: solid
+          color: [ black, black, black, black ]
+          radius: 40.5
diff --git a/wrench/reftests/border/border-suite-2.png b/wrench/reftests/border/border-suite-2.png
index d18b4369ca..24c25d39c3 100644
Binary files a/wrench/reftests/border/border-suite-2.png and b/wrench/reftests/border/border-suite-2.png differ
diff --git a/wrench/reftests/border/reftest.list b/wrench/reftests/border/reftest.list
index ecd4a9d984..c68b544581 100644
--- a/wrench/reftests/border/reftest.list
+++ b/wrench/reftests/border/reftest.list
@@ -12,4 +12,4 @@ fuzzy(255,24) == border-ridge-simple.yaml border-ridge-simple-ref.yaml
 == border-image.yaml border-image-ref.png
 == border-image-crash.yaml border-image-crash-ref.yaml
 == border-image-fill.yaml border-image-fill-ref.png
-
+== border-no-bogus-line.yaml border-no-bogus-line-ref.png