--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -184,17 +184,16 @@ typedef nsStyleTransformMatrix::Transfor
 /* static */ bool nsLayoutUtils::sFontSizeInflationForceEnabled;
 /* static */ bool nsLayoutUtils::sFontSizeInflationDisabledInMasterProcess;
 /* static */ uint32_t nsLayoutUtils::sSystemFontScale;
 /* static */ uint32_t nsLayoutUtils::sZoomMaxPercent;
 /* static */ uint32_t nsLayoutUtils::sZoomMinPercent;
 /* static */ bool nsLayoutUtils::sInvalidationDebuggingIsEnabled;
 /* static */ bool nsLayoutUtils::sInterruptibleReflowEnabled;
 /* static */ bool nsLayoutUtils::sSVGTransformBoxEnabled;
-/* static */ bool nsLayoutUtils::sTextCombineUprightDigitsEnabled;
 /* static */ uint32_t nsLayoutUtils::sIdlePeriodDeadlineLimit;
 /* static */ uint32_t nsLayoutUtils::sQuiescentFramesBeforeIdlePeriod;
 
 static ViewID sScrollIdCounter = FrameMetrics::START_SCROLL_ID;
 
 typedef nsDataHashtable<nsUint64HashKey, nsIContent*> ContentMap;
 static ContentMap* sContentMap = nullptr;
 static ContentMap& GetContentMap() {
@@ -8067,18 +8066,16 @@ nsLayoutUtils::Initialize()
   Preferences::AddUintVarCache(&sZoomMinPercent,
                                "zoom.minPercent", 30);
   Preferences::AddBoolVarCache(&sInvalidationDebuggingIsEnabled,
                                "nglayout.debug.invalidation");
   Preferences::AddBoolVarCache(&sInterruptibleReflowEnabled,
                                "layout.interruptible-reflow.enabled");
   Preferences::AddBoolVarCache(&sSVGTransformBoxEnabled,
                                "svg.transform-box.enabled");
-  Preferences::AddBoolVarCache(&sTextCombineUprightDigitsEnabled,
-                               "layout.css.text-combine-upright-digits.enabled");
   Preferences::AddUintVarCache(&sIdlePeriodDeadlineLimit,
                                "layout.idle_period.time_limit",
                                DEFAULT_IDLE_PERIOD_TIME_LIMIT);
   Preferences::AddUintVarCache(&sQuiescentFramesBeforeIdlePeriod,
                                "layout.idle_period.required_quiescent_frames",
                                DEFAULT_QUIESCENT_FRAMES);
 
   nsComputedDOMStyle::RegisterPrefChangeCallbacks();

--- a/layout/base/nsLayoutUtils.h
+++ b/layout/base/nsLayoutUtils.h
@@ -2516,20 +2516,16 @@ public:
   static float MinZoom() {
     return sZoomMinPercent / 100.0f;
   }
 
   static bool SVGTransformBoxEnabled() {
     return sSVGTransformBoxEnabled;
   }
 
-  static bool TextCombineUprightDigitsEnabled() {
-    return sTextCombineUprightDigitsEnabled;
-  }
-
   static uint32_t IdlePeriodDeadlineLimit() {
     return sIdlePeriodDeadlineLimit;
   }
 
   static uint32_t QuiescentFramesBeforeIdlePeriod() {
     return sQuiescentFramesBeforeIdlePeriod;
   }
 
@@ -3126,17 +3122,16 @@ private:
   static bool sFontSizeInflationForceEnabled;
   static bool sFontSizeInflationDisabledInMasterProcess;
   static uint32_t sSystemFontScale;
   static uint32_t sZoomMaxPercent;
   static uint32_t sZoomMinPercent;
   static bool sInvalidationDebuggingIsEnabled;
   static bool sInterruptibleReflowEnabled;
   static bool sSVGTransformBoxEnabled;
-  static bool sTextCombineUprightDigitsEnabled;
   static uint32_t sIdlePeriodDeadlineLimit;
   static uint32_t sQuiescentFramesBeforeIdlePeriod;
 
   /**
    * Helper function for LogTestDataForPaint().
    */
   static void DoLogTestDataForPaint(mozilla::layers::LayerManager* aManager,
                                     ViewID aScrollId,

--- a/layout/style/nsCSSKeywordList.h
+++ b/layout/style/nsCSSKeywordList.h
@@ -230,17 +230,16 @@ CSS_KEY(darken, darken)
 CSS_KEY(dashed, dashed)
 CSS_KEY(dense, dense)
 CSS_KEY(decimal, decimal)
 CSS_KEY(default, default)
 CSS_KEY(deg, deg)
 CSS_KEY(diagonal-fractions, diagonal_fractions)
 CSS_KEY(dialog, dialog)
 CSS_KEY(difference, difference)
-CSS_KEY(digits, digits)
 CSS_KEY(disabled, disabled)
 CSS_KEY(disc, disc)
 CSS_KEY(discretionary-ligatures, discretionary_ligatures)
 CSS_KEY(distribute, distribute)
 CSS_KEY(dot, dot)
 CSS_KEY(dotted, dotted)
 CSS_KEY(double, double)
 CSS_KEY(double-circle, double_circle)

--- a/layout/style/nsCSSProps.cpp
+++ b/layout/style/nsCSSProps.cpp
@@ -1246,17 +1246,16 @@ const KTableEntry nsCSSProps::kTextJusti
   // the exact same meaning and behavior as "inter-character".
   { eCSSKeyword_distribute, StyleTextJustify::InterCharacter },
   { eCSSKeyword_UNKNOWN, -1 }
 };
 
 const KTableEntry nsCSSProps::kTextCombineUprightKTable[] = {
   { eCSSKeyword_none, NS_STYLE_TEXT_COMBINE_UPRIGHT_NONE },
   { eCSSKeyword_all, NS_STYLE_TEXT_COMBINE_UPRIGHT_ALL },
-  { eCSSKeyword_digits, NS_STYLE_TEXT_COMBINE_UPRIGHT_DIGITS_2 }, // w/o number ==> 2
   { eCSSKeyword_UNKNOWN, -1 }
 };
 
 const KTableEntry nsCSSProps::kTextDecorationLineKTable[] = {
   { eCSSKeyword_none, NS_STYLE_TEXT_DECORATION_LINE_NONE },
   { eCSSKeyword_underline, NS_STYLE_TEXT_DECORATION_LINE_UNDERLINE },
   { eCSSKeyword_overline, NS_STYLE_TEXT_DECORATION_LINE_OVERLINE },
   { eCSSKeyword_line_through, NS_STYLE_TEXT_DECORATION_LINE_LINE_THROUGH },

--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -4175,27 +4175,19 @@ nsComputedDOMStyle::DoGetTextAlignLast()
 }
 
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetTextCombineUpright()
 {
   RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
   uint8_t tch = StyleText()->mTextCombineUpright;
 
-  if (tch <= NS_STYLE_TEXT_COMBINE_UPRIGHT_ALL) {
-    val->SetIdent(
-      nsCSSProps::ValueToKeywordEnum(tch,
-                                     nsCSSProps::kTextCombineUprightKTable));
-  } else if (tch <= NS_STYLE_TEXT_COMBINE_UPRIGHT_DIGITS_2) {
-    val->SetString(NS_LITERAL_STRING("digits 2"));
-  } else if (tch <= NS_STYLE_TEXT_COMBINE_UPRIGHT_DIGITS_3) {
-    val->SetString(NS_LITERAL_STRING("digits 3"));
-  } else {
-    val->SetString(NS_LITERAL_STRING("digits 4"));
-  }
+  val->SetIdent(
+    nsCSSProps::ValueToKeywordEnum(tch,
+                                   nsCSSProps::kTextCombineUprightKTable));
 
   return val.forget();
 }
 
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetTextDecoration()
 {
   const nsStyleTextReset* textReset = StyleTextReset();

--- a/layout/style/nsStyleConsts.h
+++ b/layout/style/nsStyleConsts.h
@@ -894,19 +894,16 @@ enum class StyleWhiteSpace : uint8_t {
 // See nsStyleText
 #define NS_STYLE_TEXT_ORIENTATION_MIXED          0
 #define NS_STYLE_TEXT_ORIENTATION_UPRIGHT        1
 #define NS_STYLE_TEXT_ORIENTATION_SIDEWAYS       2
 
 // See nsStyleText
 #define NS_STYLE_TEXT_COMBINE_UPRIGHT_NONE        0
 #define NS_STYLE_TEXT_COMBINE_UPRIGHT_ALL         1
-#define NS_STYLE_TEXT_COMBINE_UPRIGHT_DIGITS_2    2
-#define NS_STYLE_TEXT_COMBINE_UPRIGHT_DIGITS_3    3
-#define NS_STYLE_TEXT_COMBINE_UPRIGHT_DIGITS_4    4
 
 // See nsStyleText
 #define NS_STYLE_LINE_HEIGHT_BLOCK_HEIGHT       0
 
 // See nsStyleText
 #define NS_STYLE_UNICODE_BIDI_NORMAL            0x0
 #define NS_STYLE_UNICODE_BIDI_EMBED             0x1
 #define NS_STYLE_UNICODE_BIDI_ISOLATE           0x2

--- a/layout/style/test/property_database.js
+++ b/layout/style/test/property_database.js
@@ -6315,21 +6315,16 @@ if (IsCSSPropertyPrefEnabled("layout.css
                  "pan-x pan-y pan-x", "pan-x pan-x pan-y", "pan-y pan-x pan-x", "pan-y pan-x pan-y", "pan-y pan-y pan-x", "pan-x pan-y pan-y",
                  "manipulation none", "none manipulation", "manipulation auto", "auto manipulation", "manipulation zoom", "zoom manipulation",
                  "manipulation manipulation", "manipulation pan-x", "pan-x manipulation", "manipulation pan-y", "pan-y manipulation",
                  "manipulation pan-x pan-y", "pan-x manipulation pan-y", "pan-x pan-y manipulation",
                  "manipulation pan-y pan-x", "pan-y manipulation pan-x", "pan-y pan-x manipulation"]
     };
 }
 
-if (IsCSSPropertyPrefEnabled("layout.css.text-combine-upright-digits.enabled")) {
-  gCSSProperties["text-combine-upright"].other_values.push(
-    "digits", "digits 2", "digits 3", "digits 4", "digits     3");
-}
-
 if (IsCSSPropertyPrefEnabled("layout.css.text-justify.enabled")) {
   gCSSProperties["text-justify"] = {
     domProp: "textJustify",
     inherited: true,
     type: CSS_TYPE_LONGHAND,
     applies_to_placeholder: true,
     initial_values: [ "auto" ],
     other_values: [ "none", "inter-word", "inter-character", "distribute" ],

--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -2905,19 +2905,16 @@ pref("layout.css.prefixes.transforms", t
 pref("layout.css.prefixes.transitions", true);
 pref("layout.css.prefixes.animations", true);
 pref("layout.css.prefixes.box-sizing", true);
 pref("layout.css.prefixes.font-features", true);
 
 // Is support for background-blend-mode enabled?
 pref("layout.css.background-blend-mode.enabled", true);
 
-// Is support for CSS text-combine-upright: digits 2-4 enabled?
-pref("layout.css.text-combine-upright-digits.enabled", false);
-
 // Is -moz-osx-font-smoothing enabled?
 // Only supported in OSX builds
 #ifdef XP_MACOSX
 pref("layout.css.osx-font-smoothing.enabled", true);
 #else
 pref("layout.css.osx-font-smoothing.enabled", false);
 #endif