diff --git a/dom/interfaces/css/nsIDOMCSS2Properties.idl b/dom/interfaces/css/nsIDOMCSS2Properties.idl
index 2a968befb87..2942e572dfe 100644
--- a/dom/interfaces/css/nsIDOMCSS2Properties.idl
+++ b/dom/interfaces/css/nsIDOMCSS2Properties.idl
@@ -51,7 +51,7 @@
  * http://www.w3.org/TR/DOM-Level-2-Style
  */
 
-[builtinclass, scriptable, uuid(519ae4fa-0fee-4aaa-bcb9-34b503236801)]
+[builtinclass, scriptable, uuid(0a6fc4c6-a62a-4f52-9ab6-3d398b958843)]
 interface nsIDOMCSS2Properties : nsISupports
 {
            attribute DOMString        background;
@@ -764,4 +764,7 @@ interface nsIDOMCSS2Properties : nsISupports
 
            attribute DOMString        MozAnimation;
                                         // raises(DOMException) on setting
+
+           attribute DOMString        MozTextSizeAdjust;
+                                        // raises(DOMException) on setting
 };
diff --git a/layout/base/nsStyleConsts.h b/layout/base/nsStyleConsts.h
index 68985b6471d..7b0cec3c219 100644
--- a/layout/base/nsStyleConsts.h
+++ b/layout/base/nsStyleConsts.h
@@ -713,6 +713,10 @@ static inline mozilla::css::Side operator++(mozilla::css::Side& side, int) {
 #define NS_STYLE_HYPHENS_MANUAL                 1
 #define NS_STYLE_HYPHENS_AUTO                   2
 
+// See nsStyleText
+#define NS_STYLE_TEXT_SIZE_ADJUST_NONE          0
+#define NS_STYLE_TEXT_SIZE_ADJUST_AUTO          1
+
 // See nsStyleText
 #define NS_STYLE_LINE_HEIGHT_BLOCK_HEIGHT       0
 
diff --git a/layout/style/nsCSSPropList.h b/layout/style/nsCSSPropList.h
index a075798442f..69268eee5a4 100644
--- a/layout/style/nsCSSPropList.h
+++ b/layout/style/nsCSSPropList.h
@@ -2235,6 +2235,15 @@ CSS_PROP_TEXT(
     nsnull,
     offsetof(nsStyleText, mTextShadow),
     eStyleAnimType_Shadow)
+CSS_PROP_TEXT(
+    -moz-text-size-adjust,
+    text_size_adjust,
+    CSS_PROP_DOMPROP_PREFIXED(TextSizeAdjust),
+    CSS_PROPERTY_PARSE_VALUE,
+    VARIANT_AUTO | VARIANT_NONE | VARIANT_INHERIT,
+    nsnull,
+    CSS_PROP_NO_OFFSET,
+    eStyleAnimType_None)
 CSS_PROP_TEXT(
     text-transform,
     text_transform,
diff --git a/layout/style/nsComputedDOMStyle.cpp b/layout/style/nsComputedDOMStyle.cpp
index 5363e010fbe..a0eebfff543 100644
--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -2643,6 +2643,24 @@ nsComputedDOMStyle::DoGetHyphens()
   return val;
 }
 
+nsIDOMCSSValue*
+nsComputedDOMStyle::DoGetTextSizeAdjust()
+{
+  nsROCSSPrimitiveValue *val = GetROCSSPrimitiveValue();
+  switch (GetStyleText()->mTextSizeAdjust) {
+    default:
+      NS_NOTREACHED("unexpected value");
+      // fall through
+    case NS_STYLE_TEXT_SIZE_ADJUST_AUTO:
+      val->SetIdent(eCSSKeyword_auto);
+      break;
+    case NS_STYLE_TEXT_SIZE_ADJUST_NONE:
+      val->SetIdent(eCSSKeyword_none);
+      break;
+  }
+  return val;
+}
+
 nsIDOMCSSValue*
 nsComputedDOMStyle::DoGetPointerEvents()
 {
@@ -4579,6 +4597,7 @@ nsComputedDOMStyle::GetQueryablePropertyMap(PRUint32* aLength)
     COMPUTED_STYLE_MAP_ENTRY(text_decoration_color,         MozTextDecorationColor),
     COMPUTED_STYLE_MAP_ENTRY(text_decoration_line,          MozTextDecorationLine),
     COMPUTED_STYLE_MAP_ENTRY(text_decoration_style,         MozTextDecorationStyle),
+    COMPUTED_STYLE_MAP_ENTRY(text_size_adjust,              TextSizeAdjust),
     COMPUTED_STYLE_MAP_ENTRY_LAYOUT(_moz_transform,         MozTransform),
     COMPUTED_STYLE_MAP_ENTRY_LAYOUT(_moz_transform_origin,  MozTransformOrigin),
     COMPUTED_STYLE_MAP_ENTRY(transform_style,               MozTransformStyle),
diff --git a/layout/style/nsComputedDOMStyle.h b/layout/style/nsComputedDOMStyle.h
index 37e95178631..d1a432136bd 100644
--- a/layout/style/nsComputedDOMStyle.h
+++ b/layout/style/nsComputedDOMStyle.h
@@ -322,6 +322,7 @@ private:
   nsIDOMCSSValue* DoGetWordWrap();
   nsIDOMCSSValue* DoGetHyphens();
   nsIDOMCSSValue* DoGetMozTabSize();
+  nsIDOMCSSValue* DoGetTextSizeAdjust();
 
   /* Visibility properties */
   nsIDOMCSSValue* DoGetOpacity();
diff --git a/layout/style/nsRuleNode.cpp b/layout/style/nsRuleNode.cpp
index 27336bf8ea5..2e7a332edad 100644
--- a/layout/style/nsRuleNode.cpp
+++ b/layout/style/nsRuleNode.cpp
@@ -3398,6 +3398,15 @@ nsRuleNode::ComputeTextData(void* aStartStruct,
               SETDSC_ENUMERATED, parentText->mHyphens,
               NS_STYLE_HYPHENS_MANUAL, 0, 0, 0, 0);
 
+  // text-size-adjust: none, auto, inherit, initial
+  SetDiscrete(*aRuleData->ValueForTextSizeAdjust(), text->mTextSizeAdjust,
+              canStoreInRuleTree, SETDSC_NONE | SETDSC_AUTO,
+              parentText->mTextSizeAdjust,
+              NS_STYLE_TEXT_SIZE_ADJUST_AUTO, // initial value
+              NS_STYLE_TEXT_SIZE_ADJUST_AUTO, // auto value
+              NS_STYLE_TEXT_SIZE_ADJUST_NONE, // none value
+              0, 0);
+
   COMPUTE_END_INHERITED(Text, text)
 }
 
diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index 988070a0bd2..559b45d60ca 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -2800,6 +2800,7 @@ nsStyleText::nsStyleText(void)
   mWhiteSpace = NS_STYLE_WHITESPACE_NORMAL;
   mWordWrap = NS_STYLE_WORDWRAP_NORMAL;
   mHyphens = NS_STYLE_HYPHENS_MANUAL;
+  mTextSizeAdjust = NS_STYLE_TEXT_SIZE_ADJUST_AUTO;
 
   mLetterSpacing.SetNormalValue();
   mLineHeight.SetNormalValue();
@@ -2816,6 +2817,7 @@ nsStyleText::nsStyleText(const nsStyleText& aSource)
     mWhiteSpace(aSource.mWhiteSpace),
     mWordWrap(aSource.mWordWrap),
     mHyphens(aSource.mHyphens),
+    mTextSizeAdjust(aSource.mTextSizeAdjust),
     mTabSize(aSource.mTabSize),
     mLetterSpacing(aSource.mLetterSpacing),
     mLineHeight(aSource.mLineHeight),
@@ -2843,6 +2845,7 @@ nsChangeHint nsStyleText::CalcDifference(const nsStyleText& aOther) const
       (mWhiteSpace != aOther.mWhiteSpace) ||
       (mWordWrap != aOther.mWordWrap) ||
       (mHyphens != aOther.mHyphens) ||
+      (mTextSizeAdjust != aOther.mTextSizeAdjust) ||
       (mLetterSpacing != aOther.mLetterSpacing) ||
       (mLineHeight != aOther.mLineHeight) ||
       (mTextIndent != aOther.mTextIndent) ||
diff --git a/layout/style/nsStyleStruct.h b/layout/style/nsStyleStruct.h
index 332b089d570..d8114caec12 100644
--- a/layout/style/nsStyleStruct.h
+++ b/layout/style/nsStyleStruct.h
@@ -1280,6 +1280,7 @@ struct nsStyleText {
   PRUint8 mWhiteSpace;                  // [inherited] see nsStyleConsts.h
   PRUint8 mWordWrap;                    // [inherited] see nsStyleConsts.h
   PRUint8 mHyphens;                     // [inherited] see nsStyleConsts.h
+  PRUint8 mTextSizeAdjust;              // [inherited] see nsStyleConsts.h
   PRInt32 mTabSize;                     // [inherited] see nsStyleConsts.h
 
   nsStyleCoord  mLetterSpacing;         // [inherited] coord, normal
diff --git a/layout/style/test/property_database.js b/layout/style/test/property_database.js
index 1e20b45c21b..7d7f231f566 100644
--- a/layout/style/test/property_database.js
+++ b/layout/style/test/property_database.js
@@ -925,6 +925,14 @@ var gCSSProperties = {
 		other_values: [ "0", "3", "99", "12000" ],
 		invalid_values: [ "-1", "-808", "3.0", "17.5" ]
 	},
+	"-moz-text-size-adjust": {
+		domProp: "MozTextSizeAdjust",
+		inherited: true,
+		type: CSS_TYPE_LONGHAND,
+		initial_values: [ "auto" ],
+		other_values: [ "none" ],
+		invalid_values: [ "-5%", "0", "100", "0%", "50%", "100%", "220.3%" ]
+	},
 	"-moz-transform": {
 		domProp: "MozTransform",
 		inherited: false,