--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -137,17 +137,16 @@ using namespace mozilla;
 using namespace mozilla::dom;
 using namespace mozilla::image;
 using namespace mozilla::layers;
 using namespace mozilla::layout;
 using namespace mozilla::gfx;
 
 #define GRID_ENABLED_PREF_NAME "layout.css.grid.enabled"
 #define GRID_TEMPLATE_SUBGRID_ENABLED_PREF_NAME "layout.css.grid-template-subgrid-value.enabled"
-#define STICKY_ENABLED_PREF_NAME "layout.css.sticky.enabled"
 #define DISPLAY_CONTENTS_ENABLED_PREF_NAME "layout.css.display-contents.enabled"
 #define TEXT_ALIGN_UNSAFE_ENABLED_PREF_NAME "layout.css.text-align-unsafe-value.enabled"
 #define FLOAT_LOGICAL_VALUES_ENABLED_PREF_NAME "layout.css.float-logical-values.enabled"
 
 #ifdef DEBUG
 // TODO: remove, see bug 598468.
 bool nsLayoutUtils::gPreventAssertInCompareTreePosition = false;
 #endif // DEBUG
@@ -218,49 +217,16 @@ GridEnabledPrefChangeCallback(const char
       isGridEnabled ? eCSSKeyword_grid : eCSSKeyword_UNKNOWN;
   }
   if (sIndexOfInlineGridInDisplayTable >= 0) {
     nsCSSProps::kDisplayKTable[sIndexOfInlineGridInDisplayTable].mKeyword =
       isGridEnabled ? eCSSKeyword_inline_grid : eCSSKeyword_UNKNOWN;
   }
 }
 
-// When the pref "layout.css.sticky.enabled" changes, this function is invoked
-// to let us update kPositionKTable, to selectively disable or restore the
-// entry for "sticky" in that table.
-static void
-StickyEnabledPrefChangeCallback(const char* aPrefName, void* aClosure)
-{
-  MOZ_ASSERT(strncmp(aPrefName, STICKY_ENABLED_PREF_NAME,
-                     ArrayLength(STICKY_ENABLED_PREF_NAME)) == 0,
-             "We only registered this callback for a single pref, so it "
-             "should only be called for that pref");
-
-  static int32_t sIndexOfStickyInPositionTable;
-  static bool sIsStickyKeywordIndexInitialized; // initialized to false
-
-  bool isStickyEnabled =
-    Preferences::GetBool(STICKY_ENABLED_PREF_NAME, false);
-
-  if (!sIsStickyKeywordIndexInitialized) {
-    // First run: find the position of "sticky" in kPositionKTable.
-    sIndexOfStickyInPositionTable =
-      nsCSSProps::FindIndexOfKeyword(eCSSKeyword_sticky,
-                                     nsCSSProps::kPositionKTable);
-    MOZ_ASSERT(sIndexOfStickyInPositionTable >= 0,
-               "Couldn't find sticky in kPositionKTable");
-    sIsStickyKeywordIndexInitialized = true;
-  }
-
-  // OK -- now, stomp on or restore the "sticky" entry in kPositionKTable,
-  // depending on whether the sticky pref is enabled vs. disabled.
-  nsCSSProps::kPositionKTable[sIndexOfStickyInPositionTable].mKeyword =
-    isStickyEnabled ? eCSSKeyword_sticky : eCSSKeyword_UNKNOWN;
-}
-
 // When the pref "layout.css.display-contents.enabled" changes, this function is
 // invoked to let us update kDisplayKTable, to selectively disable or restore
 // the entries for "contents" in that table.
 static void
 DisplayContentsEnabledPrefChangeCallback(const char* aPrefName, void* aClosure)
 {
   NS_ASSERTION(strcmp(aPrefName, DISPLAY_CONTENTS_ENABLED_PREF_NAME) == 0,
                "Did you misspell " DISPLAY_CONTENTS_ENABLED_PREF_NAME " ?");
@@ -7594,19 +7560,16 @@ nsLayoutUtils::Initialize()
   Preferences::AddBoolVarCache(&sInterruptibleReflowEnabled,
                                "layout.interruptible-reflow.enabled");
   Preferences::AddBoolVarCache(&sSVGTransformBoxEnabled,
                                "svg.transform-box.enabled");
 
   Preferences::RegisterCallback(GridEnabledPrefChangeCallback,
                                 GRID_ENABLED_PREF_NAME);
   GridEnabledPrefChangeCallback(GRID_ENABLED_PREF_NAME, nullptr);
-  Preferences::RegisterCallback(StickyEnabledPrefChangeCallback,
-                                STICKY_ENABLED_PREF_NAME);
-  StickyEnabledPrefChangeCallback(STICKY_ENABLED_PREF_NAME, nullptr);
   Preferences::RegisterCallback(TextAlignUnsafeEnabledPrefChangeCallback,
                                 TEXT_ALIGN_UNSAFE_ENABLED_PREF_NAME);
   Preferences::RegisterCallback(DisplayContentsEnabledPrefChangeCallback,
                                 DISPLAY_CONTENTS_ENABLED_PREF_NAME);
   DisplayContentsEnabledPrefChangeCallback(DISPLAY_CONTENTS_ENABLED_PREF_NAME,
                                            nullptr);
   TextAlignUnsafeEnabledPrefChangeCallback(TEXT_ALIGN_UNSAFE_ENABLED_PREF_NAME,
                                            nullptr);
@@ -7624,19 +7587,16 @@ nsLayoutUtils::Shutdown()
 {
   if (sContentMap) {
     delete sContentMap;
     sContentMap = nullptr;
   }
 
   Preferences::UnregisterCallback(GridEnabledPrefChangeCallback,
                                   GRID_ENABLED_PREF_NAME);
-  Preferences::UnregisterCallback(StickyEnabledPrefChangeCallback,
-                                  STICKY_ENABLED_PREF_NAME);
-
   nsComputedDOMStyle::UnregisterPrefChangeCallbacks();
 }
 
 /* static */
 void
 nsLayoutUtils::RegisterImageRequest(nsPresContext* aPresContext,
                                     imgIRequest* aRequest,
                                     bool* aRequestRegistered)

--- a/layout/style/nsCSSProps.cpp
+++ b/layout/style/nsCSSProps.cpp
@@ -1857,22 +1857,21 @@ const KTableEntry nsCSSProps::kPointerEv
   { eCSSKeyword_painted, NS_STYLE_POINTER_EVENTS_PAINTED },
   { eCSSKeyword_fill, NS_STYLE_POINTER_EVENTS_FILL },
   { eCSSKeyword_stroke, NS_STYLE_POINTER_EVENTS_STROKE },
   { eCSSKeyword_all, NS_STYLE_POINTER_EVENTS_ALL },
   { eCSSKeyword_auto, NS_STYLE_POINTER_EVENTS_AUTO },
   { eCSSKeyword_UNKNOWN, -1 }
 };
 
-KTableEntry nsCSSProps::kPositionKTable[] = {
+const KTableEntry nsCSSProps::kPositionKTable[] = {
   { eCSSKeyword_static, NS_STYLE_POSITION_STATIC },
   { eCSSKeyword_relative, NS_STYLE_POSITION_RELATIVE },
   { eCSSKeyword_absolute, NS_STYLE_POSITION_ABSOLUTE },
   { eCSSKeyword_fixed, NS_STYLE_POSITION_FIXED },
-  // The next entry is controlled by the layout.css.sticky.enabled pref.
   { eCSSKeyword_sticky, NS_STYLE_POSITION_STICKY },
   { eCSSKeyword_UNKNOWN, -1 }
 };
 
 const KTableEntry nsCSSProps::kRadialGradientShapeKTable[] = {
   { eCSSKeyword_circle,  NS_STYLE_GRADIENT_SHAPE_CIRCULAR },
   { eCSSKeyword_ellipse, NS_STYLE_GRADIENT_SHAPE_ELLIPTICAL },
   { eCSSKeyword_UNKNOWN, -1 }

--- a/layout/style/nsCSSProps.h
+++ b/layout/style/nsCSSProps.h
@@ -789,19 +789,17 @@ public:
   static const KTableEntry kOverflowSubKTable[];
   static const KTableEntry kOverflowClipBoxKTable[];
   static const KTableEntry kPageBreakKTable[];
   static const KTableEntry kPageBreakInsideKTable[];
   static const KTableEntry kPageMarksKTable[];
   static const KTableEntry kPageSizeKTable[];
   static const KTableEntry kPitchKTable[];
   static const KTableEntry kPointerEventsKTable[];
-  // Not const because we modify its entries when the pref
-  // "layout.css.sticky.enabled" changes:
-  static KTableEntry kPositionKTable[];
+  static const KTableEntry kPositionKTable[];
   static const KTableEntry kRadialGradientShapeKTable[];
   static const KTableEntry kRadialGradientSizeKTable[];
   static const KTableEntry kRadialGradientLegacySizeKTable[];
   static const KTableEntry kResizeKTable[];
   static const KTableEntry kRubyAlignKTable[];
   static const KTableEntry kRubyPositionKTable[];
   static const KTableEntry kScrollBehaviorKTable[];
   static const KTableEntry kScrollSnapTypeKTable[];

--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -2335,19 +2335,16 @@ pref("layout.css.scroll-snap.prediction-
 // scroll frame is integrated over this duration, in seconds.  The snap point
 // best suited for this position is selected, enabling the user to perform fling
 // gestures.
 pref("layout.css.scroll-snap.prediction-sensitivity", "0.750");
 
 // Is support for basic shapes in clip-path enabled?
 pref("layout.css.clip-path-shapes.enabled", false);
 
-// Is support for CSS sticky positioning enabled?
-pref("layout.css.sticky.enabled", true);
-
 // Is support for DOMPoint enabled?
 pref("layout.css.DOMPoint.enabled", true);
 
 // Is support for DOMQuad enabled?
 pref("layout.css.DOMQuad.enabled", true);
 
 // Is support for DOMMatrix enabled?
 pref("layout.css.DOMMatrix.enabled", true);