--- a/layout/mathml/nsMathMLmfracFrame.cpp
+++ b/layout/mathml/nsMathMLmfracFrame.cpp
@@ -311,16 +311,20 @@ nsresult nsMathMLmfracFrame::PlaceIntern
       nscoord minClearance =
           displayStyle ? 7 * defaultRuleThickness : 3 * defaultRuleThickness;
       if (mathFont) {
         minClearance = mathFont->MathTable()->Constant(
             displayStyle ? gfxMathTable::StackDisplayStyleGapMin
                          : gfxMathTable::StackGapMin,
             oneDevPixel);
       }
+      // Factor in axis height
+      // http://www.mathml-association.org/MathMLinHTML5/S3.html#SS3.SSS2
+      numShift += axisHeight;
+      denShift += axisHeight;
 
       nscoord actualClearance =
           (numShift - bmNum.descent) - (bmDen.ascent - denShift);
       // actualClearance should be >= minClearance
       if (actualClearance < minClearance) {
         nscoord halfGap = (minClearance - actualClearance) / 2;
         numShift += halfGap;
         denShift += halfGap;

new file mode 100644
--- /dev/null
+++ b/testing/web-platform/meta/mathml/presentation-markup/fractions/frac-parameters-2.html.ini
@@ -0,0 +1,13 @@
+[frac-parameters-2.html]
+  [TopDisplayStyleShiftUp]
+    expected: FAIL
+
+  [BottomDisplayStyleShiftDown]
+    expected: FAIL
+
+  [BottomShiftDown]
+    expected: FAIL
+
+  [ToShiftUp]
+    expected: FAIL
+