diff --git a/gfx/src/nsFont.cpp b/gfx/src/nsFont.cpp
index f493633a9f6d..bd3c905fa901 100644
--- a/gfx/src/nsFont.cpp
+++ b/gfx/src/nsFont.cpp
@@ -48,6 +48,7 @@ nsFont::Init()
   sizeAdjust = -1.0f;
   kerning = NS_FONT_KERNING_AUTO;
   synthesis = NS_FONT_SYNTHESIS_WEIGHT | NS_FONT_SYNTHESIS_STYLE;
+  decorations = 0;
 
   variantAlternates = 0;
   variantCaps = NS_FONT_VARIANT_CAPS_NORMAL;
@@ -64,6 +65,7 @@ nsFont::nsFont(const nsFont& aOther)
   systemFont = aOther.systemFont;
   weight = aOther.weight;
   stretch = aOther.stretch;
+  decorations = aOther.decorations;
   smoothing = aOther.smoothing;
   size = aOther.size;
   sizeAdjust = aOther.sizeAdjust;
@@ -116,6 +118,15 @@ bool nsFont::BaseEquals(const nsFont& aOther) const
   return false;
 }
 
+bool nsFont::Equals(const nsFont& aOther) const
+{
+  if (BaseEquals(aOther) &&
+      (decorations == aOther.decorations)) {
+    return true;
+  }
+  return false;
+}
+
 nsFont& nsFont::operator=(const nsFont& aOther)
 {
   fontlist = aOther.fontlist;
@@ -123,6 +134,7 @@ nsFont& nsFont::operator=(const nsFont& aOther)
   systemFont = aOther.systemFont;
   weight = aOther.weight;
   stretch = aOther.stretch;
+  decorations = aOther.decorations;
   smoothing = aOther.smoothing;
   size = aOther.size;
   sizeAdjust = aOther.sizeAdjust;
diff --git a/gfx/src/nsFont.h b/gfx/src/nsFont.h
index 68f1c2acb1ab..7b4137543985 100644
--- a/gfx/src/nsFont.h
+++ b/gfx/src/nsFont.h
@@ -66,6 +66,10 @@ struct nsFont {
   // -- bitmask for both enumerated and functional propvals
   uint16_t variantAlternates;
 
+  // The decorations on the font (underline, overline,
+  // line-through). The decorations can be binary or'd together.
+  uint8_t decorations;
+
   // Smoothing - controls subpixel-antialiasing (currently OSX only)
   uint8_t smoothing;
 
@@ -123,11 +127,8 @@ struct nsFont {
     return Equals(aOther);
   }
 
-  // FIXME (in patch 3): These are now the same.  Remove BaseEquals!
-  bool Equals(const nsFont& aOther) const
-  {
-    return BaseEquals(aOther);
-  }
+  bool Equals(const nsFont& aOther) const ;
+  // Compare ignoring differences in 'variant' and 'decoration'
   bool BaseEquals(const nsFont& aOther) const;
 
   nsFont& operator=(const nsFont& aOther);
diff --git a/layout/style/nsRuleNode.cpp b/layout/style/nsRuleNode.cpp
index 7b3a3996db14..9fee0a12abb2 100644
--- a/layout/style/nsRuleNode.cpp
+++ b/layout/style/nsRuleNode.cpp
@@ -3413,6 +3413,7 @@ nsRuleNode::SetFont(nsPresContext* aPresContext, nsStyleContext* aContext,
       systemFont.systemFont = fontStyle.systemFont;
       systemFont.weight = fontStyle.weight;
       systemFont.stretch = fontStyle.stretch;
+      systemFont.decorations = NS_FONT_DECORATION_NONE;
       systemFont.size =
         NSFloatPixelsToAppUnits(fontStyle.size,
                                 aPresContext->DeviceContext()->
diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index 59923d86b0d9..633c2bd35a68 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -251,7 +251,10 @@ nsChangeHint nsStyleFont::CalcFontDifference(const nsFont& aFont1, const nsFont&
       (aFont1.fontFeatureSettings == aFont2.fontFeatureSettings) &&
       (aFont1.languageOverride == aFont2.languageOverride) &&
       (aFont1.systemFont == aFont2.systemFont)) {
-    return NS_STYLE_HINT_NONE;
+    if ((aFont1.decorations == aFont2.decorations)) {
+      return NS_STYLE_HINT_NONE;
+    }
+    return nsChangeHint_RepaintFrame;
   }
   return NS_STYLE_HINT_REFLOW;
 }