diff --git a/mathml/presentation-markup/spaces/space-like-001.html b/mathml/presentation-markup/spaces/space-like-001.html
index 61375bcd8e320b..62ad0f1278e299 100644
--- a/mathml/presentation-markup/spaces/space-like-001.html
+++ b/mathml/presentation-markup/spaces/space-like-001.html
@@ -108,6 +108,18 @@
           assert_approx_equals(spaceAfter("mpadded2"), 2 * emToPx, epsilon);
       }, "non-space-like mpadded");
 
+      test(function() {
+          assert_true(MathMLFeatureDetection.has_operator_spacing());
+          assert_approx_equals(spaceBefore("merror1"), emToPx, epsilon);
+          assert_approx_equals(spaceAfter("merror1"), emToPx, epsilon);
+      }, "space-like merror");
+
+      test(function() {
+          assert_true(MathMLFeatureDetection.has_operator_spacing());
+          assert_approx_equals(spaceBefore("merror2"), 0, epsilon);
+          assert_approx_equals(spaceAfter("merror2"), 2 * emToPx, epsilon);
+      }, "non-space-like merror");
+
       done();
   }
 </script>
@@ -253,5 +265,34 @@
       <mn>X</mn>
     </math>
   </p>
+  <p>
+    <math>
+      <mn>X</mn>
+      <mrow>
+        <!-- merror is space-like when it contains only space-like elements. -->
+        <merror id="merror1" class="testedElement">
+          <mtext>X</mtext>
+          <mspace width="25px" height="10px"></mspace>
+        </merror>
+        <mo lspace="1em" rspace="0em">X</mo>
+      </mrow>
+      <mn>X</mn>
+    </math>
+  </p>
+  <p>
+    <math>
+      <mn>X</mn>
+      <mrow>
+        <!-- merror is not space-like when it contains a non space-like element
+             such as "mn". -->
+        <merror id="merror2" class="testedElement">
+          <mn>X</mn>
+          <mspace width="25px" height="10px"></mspace>
+        </merror>
+        <mo lspace="1em" rspace="0em">X</mo>
+      </mrow>
+      <mn>X</mn>
+    </math>
+  </p>
 </body>
 </html>
diff --git a/mathml/presentation-markup/spaces/space-like-002.html b/mathml/presentation-markup/spaces/space-like-002.html
index f5f4e5a84b2481..b12c61b34ba032 100644
--- a/mathml/presentation-markup/spaces/space-like-002.html
+++ b/mathml/presentation-markup/spaces/space-like-002.html
@@ -56,9 +56,9 @@
 
       test(function() {
           assert_true(MathMLFeatureDetection.has_operator_spacing());
-          assert_approx_equals(spaceBefore("maction2"), 0, epsilon);
-          assert_approx_equals(spaceAfter("maction2"), 2 * emToPx, epsilon);
-      }, "non-space like maction (no first child)");
+          assert_approx_equals(spaceBefore("maction2"), emToPx, epsilon);
+          assert_approx_equals(spaceAfter("maction2"), emToPx, epsilon);
+      }, "space-like maction (no first child)");
 
       test(function() {
           assert_approx_equals(spaceBefore("maction3"), 0, epsilon);
@@ -74,9 +74,9 @@
 
       test(function() {
           assert_true(MathMLFeatureDetection.has_operator_spacing());
-          assert_approx_equals(spaceBefore("semantics2"), 0, epsilon);
-          assert_approx_equals(spaceAfter("semantics2"), 2 * emToPx, epsilon);
-      }, "non-space like semantics (no first child)");
+          assert_approx_equals(spaceBefore("semantics2"), emToPx, epsilon);
+          assert_approx_equals(spaceAfter("semantics2"), emToPx, epsilon);
+      }, "space-like semantics (no first child)");
 
       test(function() {
           assert_true(MathMLFeatureDetection.has_operator_spacing());
diff --git a/mathml/presentation-markup/spaces/space-like-003.html b/mathml/presentation-markup/spaces/space-like-003.html
index 6d3d007744e7a3..7398ebe2d56656 100644
--- a/mathml/presentation-markup/spaces/space-like-003.html
+++ b/mathml/presentation-markup/spaces/space-like-003.html
@@ -60,18 +60,6 @@
 </head>
 <body>
   <div id="log"></div>
-  <p>
-    <math>
-      <mn>X</mn>
-      <mrow>
-        <merror class="testedElement">
-          <mtext>X</mtext>
-        </merror>
-        <mo lspace="1em" rspace="0em">X</mo>
-      </mrow>
-      <mn>X</mn>
-    </math>
-  </p>
   <p>
     <math>
       <mn>X</mn>
