diff --git a/html/canvas/element/text/2d.text.measure.actualBoundingBox.whitespace.html b/html/canvas/element/text/2d.text.measure.actualBoundingBox.whitespace.html
index 29f25f502d7d80..1e389a19264b63 100644
--- a/html/canvas/element/text/2d.text.measure.actualBoundingBox.whitespace.html
+++ b/html/canvas/element/text/2d.text.measure.actualBoundingBox.whitespace.html
@@ -38,11 +38,16 @@ <h1>2d.text.measure.actualBoundingBox.whitespace</h1>
   // Values that are nominally expected to be zero might actually vary by a
   // pixel or so if the UA accounts for antialiasing at glyph edges, so we
   // allow a slight deviation.
-  _assert(Math.abs(ctx.measureText('A ').actualBoundingBoxLeft) <= 1, "Math.abs(ctx.measureText('A ').actualBoundingBoxLeft) <= 1");
-  _assert(ctx.measureText('A ').actualBoundingBoxRight >= 50, "ctx.measureText('A ').actualBoundingBoxRight >= 50");
+  var whitespaces = [0x9, 0xa, 0xc, 0xd, 0x20, 0x3000];
+  for (var codepoint of whitespaces) {
+    let whitespace = String.fromCharCode(codepoint);
 
-  _assert(Math.abs(ctx.measureText(' A').actualBoundingBoxLeft) >= 49, "Math.abs(ctx.measureText(' A').actualBoundingBoxLeft) >= 49");
-  _assert(ctx.measureText(' A').actualBoundingBoxRight <= 101, "ctx.measureText(' A').actualBoundingBoxRight <= 101");
+    _assert(Math.abs(ctx.measureText('A' + whitespace).actualBoundingBoxLeft) <= 1, "Math.abs(ctx.measureText('A' + whitespace).actualBoundingBoxLeft) <= 1");
+    _assert(ctx.measureText('A' + whitespace).actualBoundingBoxRight >= 50, "ctx.measureText('A' + whitespace).actualBoundingBoxRight >= 50");
+
+    _assert(Math.abs(ctx.measureText(whitespace + 'A').actualBoundingBoxLeft) >= 49, "Math.abs(ctx.measureText(whitespace + 'A').actualBoundingBoxLeft) >= 49");
+    _assert(ctx.measureText(whitespace + 'A').actualBoundingBoxRight <= 101, "ctx.measureText(whitespace + 'A').actualBoundingBoxRight <= 101");
+  }
 
 }, "Testing actualBoundingBox with leading/trailing whitespace");
 </script>
diff --git a/html/canvas/offscreen/text/2d.text.measure.actualBoundingBox.whitespace.html b/html/canvas/offscreen/text/2d.text.measure.actualBoundingBox.whitespace.html
index e9bed7dcefd3bf..5895e6360a0725 100644
--- a/html/canvas/offscreen/text/2d.text.measure.actualBoundingBox.whitespace.html
+++ b/html/canvas/offscreen/text/2d.text.measure.actualBoundingBox.whitespace.html
@@ -28,11 +28,16 @@ <h1>2d.text.measure.actualBoundingBox.whitespace</h1>
   // Values that are nominally expected to be zero might actually vary by a
   // pixel or so if the UA accounts for antialiasing at glyph edges, so we
   // allow a slight deviation.
-  _assert(Math.abs(ctx.measureText('A ').actualBoundingBoxLeft) <= 1, "Math.abs(ctx.measureText('A ').actualBoundingBoxLeft) <= 1");
-  _assert(ctx.measureText('A ').actualBoundingBoxRight >= 50, "ctx.measureText('A ').actualBoundingBoxRight >= 50");
+  var whitespaces = [0x9, 0xa, 0xc, 0xd, 0x20, 0x3000];
+  for (var codepoint of whitespaces) {
+    let whitespace = String.fromCharCode(codepoint);
 
-  _assert(Math.abs(ctx.measureText(' A').actualBoundingBoxLeft) >= 49, "Math.abs(ctx.measureText(' A').actualBoundingBoxLeft) >= 49");
-  _assert(ctx.measureText(' A').actualBoundingBoxRight <= 101, "ctx.measureText(' A').actualBoundingBoxRight <= 101");
+    _assert(Math.abs(ctx.measureText('A' + whitespace).actualBoundingBoxLeft) <= 1, "Math.abs(ctx.measureText('A' + whitespace).actualBoundingBoxLeft) <= 1");
+    _assert(ctx.measureText('A' + whitespace).actualBoundingBoxRight >= 50, "ctx.measureText('A' + whitespace).actualBoundingBoxRight >= 50");
+
+    _assert(Math.abs(ctx.measureText(whitespace + 'A').actualBoundingBoxLeft) >= 49, "Math.abs(ctx.measureText(whitespace + 'A').actualBoundingBoxLeft) >= 49");
+    _assert(ctx.measureText(whitespace + 'A').actualBoundingBoxRight <= 101, "ctx.measureText(whitespace + 'A').actualBoundingBoxRight <= 101");
+  }
 
 }, "Testing actualBoundingBox with leading/trailing whitespace");
 </script>
diff --git a/html/canvas/offscreen/text/2d.text.measure.actualBoundingBox.whitespace.worker.js b/html/canvas/offscreen/text/2d.text.measure.actualBoundingBox.whitespace.worker.js
index b588b6e68f85d1..e3b74443e42fce 100644
--- a/html/canvas/offscreen/text/2d.text.measure.actualBoundingBox.whitespace.worker.js
+++ b/html/canvas/offscreen/text/2d.text.measure.actualBoundingBox.whitespace.worker.js
@@ -22,10 +22,15 @@ promise_test(async t => {
   // Values that are nominally expected to be zero might actually vary by a
   // pixel or so if the UA accounts for antialiasing at glyph edges, so we
   // allow a slight deviation.
-  _assert(Math.abs(ctx.measureText('A ').actualBoundingBoxLeft) <= 1, "Math.abs(ctx.measureText('A ').actualBoundingBoxLeft) <= 1");
-  _assert(ctx.measureText('A ').actualBoundingBoxRight >= 50, "ctx.measureText('A ').actualBoundingBoxRight >= 50");
+  var whitespaces = [0x9, 0xa, 0xc, 0xd, 0x20, 0x3000];
+  for (var codepoint of whitespaces) {
+    let whitespace = String.fromCharCode(codepoint);
 
-  _assert(Math.abs(ctx.measureText(' A').actualBoundingBoxLeft) >= 49, "Math.abs(ctx.measureText(' A').actualBoundingBoxLeft) >= 49");
-  _assert(ctx.measureText(' A').actualBoundingBoxRight <= 101, "ctx.measureText(' A').actualBoundingBoxRight <= 101");
+    _assert(Math.abs(ctx.measureText('A' + whitespace).actualBoundingBoxLeft) <= 1, "Math.abs(ctx.measureText('A' + whitespace).actualBoundingBoxLeft) <= 1");
+    _assert(ctx.measureText('A' + whitespace).actualBoundingBoxRight >= 50, "ctx.measureText('A' + whitespace).actualBoundingBoxRight >= 50");
+
+    _assert(Math.abs(ctx.measureText(whitespace + 'A').actualBoundingBoxLeft) >= 49, "Math.abs(ctx.measureText(whitespace + 'A').actualBoundingBoxLeft) >= 49");
+    _assert(ctx.measureText(whitespace + 'A').actualBoundingBoxRight <= 101, "ctx.measureText(whitespace + 'A').actualBoundingBoxRight <= 101");
+  }
 }, "Testing actualBoundingBox with leading/trailing whitespace");
 done();
diff --git a/html/canvas/tools/yaml-new/text.yaml b/html/canvas/tools/yaml-new/text.yaml
index db2d5380dd81f2..38630509bf2f79 100644
--- a/html/canvas/tools/yaml-new/text.yaml
+++ b/html/canvas/tools/yaml-new/text.yaml
@@ -1097,11 +1097,16 @@
     // Values that are nominally expected to be zero might actually vary by a
     // pixel or so if the UA accounts for antialiasing at glyph edges, so we
     // allow a slight deviation.
-    @assert Math.abs(ctx.measureText('A ').actualBoundingBoxLeft) <= 1;
-    @assert ctx.measureText('A ').actualBoundingBoxRight >= 50;
+    var whitespaces = [0x9, 0xa, 0xc, 0xd, 0x20, 0x3000];
+    for (var codepoint of whitespaces) {
+      let whitespace = String.fromCharCode(codepoint);
 
-    @assert Math.abs(ctx.measureText(' A').actualBoundingBoxLeft) >= 49;
-    @assert ctx.measureText(' A').actualBoundingBoxRight <= 101;
+      @assert Math.abs(ctx.measureText('A' + whitespace).actualBoundingBoxLeft) <= 1;
+      @assert ctx.measureText('A' + whitespace).actualBoundingBoxRight >= 50;
+
+      @assert Math.abs(ctx.measureText(whitespace + 'A').actualBoundingBoxLeft) >= 49;
+      @assert ctx.measureText(whitespace + 'A').actualBoundingBoxRight <= 101;
+    }
   variants:
   - *load-font-variant-definition