diff --git a/gsk/gpu/shaders/gskgpuboxshadow.glsl b/gsk/gpu/shaders/gskgpuboxshadow.glsl
index 93d111c721..37bb67da7b 100644
--- a/gsk/gpu/shaders/gskgpuboxshadow.glsl
+++ b/gsk/gpu/shaders/gskgpuboxshadow.glsl
@@ -115,7 +115,7 @@ blur_corner (vec2 p,
   r /= _sigma;
 
   if (min (p.x, p.y) <= -2.95 ||
-      max (p.x, p.y) >= 2.95)
+      max (p.x - r.x, p.y - r.y) >= 2.95)
     return 0.0;
 
   float result = 0.0;
diff --git a/testsuite/gsk/compare/outset-shadow-corner-blur-normal.node b/testsuite/gsk/compare/outset-shadow-corner-blur-normal.node
new file mode 100644
index 0000000000..54f109b526
--- /dev/null
+++ b/testsuite/gsk/compare/outset-shadow-corner-blur-normal.node
@@ -0,0 +1,7 @@
+clip {
+  clip: 0 0 25 25;
+  child: outset-shadow {
+    blur: 1;
+    outline: 0 0 100 100 / 100 0 100 0;
+  }
+}
diff --git a/testsuite/gsk/compare/outset-shadow-corner-blur-normal.png b/testsuite/gsk/compare/outset-shadow-corner-blur-normal.png
new file mode 100644
index 0000000000..9f25e99855
Binary files /dev/null and b/testsuite/gsk/compare/outset-shadow-corner-blur-normal.png differ
diff --git a/testsuite/gsk/meson.build b/testsuite/gsk/meson.build
index 55f6c88726..36f8de186d 100644
--- a/testsuite/gsk/meson.build
+++ b/testsuite/gsk/meson.build
@@ -121,6 +121,7 @@ compare_render_tests = [
   'opacity-overlapping-children',
   'outset-shadow-corner-blur',
   'outset-shadow-corner-blur-huge-nocairo-nogl',
+  'outset-shadow-corner-blur-normal',
   'outset-shadow-corner-blur-tiny',
   'outset_shadow_offset_both',
   'outset_shadow_offset_x',