diff --git a/dom/canvas/CanvasGradient.h b/dom/canvas/CanvasGradient.h
index 00fbb257e27..8bcf7dfaa0c 100644
--- a/dom/canvas/CanvasGradient.h
+++ b/dom/canvas/CanvasGradient.h
@@ -23,10 +23,10 @@ public:
   NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(CanvasGradient)
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(CanvasGradient)
 
-  MOZ_BEGIN_NESTED_ENUM_CLASS(Type, uint8_t)
+  enum class Type : uint8_t {
     LINEAR = 0,
     RADIAL
-  MOZ_END_NESTED_ENUM_CLASS(Type)
+  };
 
   Type GetType()
   {
@@ -75,8 +75,6 @@ protected:
   virtual ~CanvasGradient() {}
 };
 
-MOZ_FINISH_NESTED_ENUM_CLASS(CanvasGradient::Type)
-
 } // namespace dom
 } // namespace mozilla
 
diff --git a/dom/canvas/CanvasPattern.h b/dom/canvas/CanvasPattern.h
index 9fc171d3cef..93d52ef3050 100644
--- a/dom/canvas/CanvasPattern.h
+++ b/dom/canvas/CanvasPattern.h
@@ -29,12 +29,12 @@ public:
   NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(CanvasPattern)
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(CanvasPattern)
 
-  MOZ_BEGIN_NESTED_ENUM_CLASS(RepeatMode, uint8_t)
+  enum class RepeatMode : uint8_t {
     REPEAT,
     REPEATX,
     REPEATY,
     NOREPEAT
-  MOZ_END_NESTED_ENUM_CLASS(RepeatMode)
+  };
 
   CanvasPattern(CanvasRenderingContext2D* aContext,
                 gfx::SourceSurface* aSurface,
@@ -74,8 +74,6 @@ public:
   const RepeatMode mRepeat;
 };
 
-MOZ_FINISH_NESTED_ENUM_CLASS(CanvasPattern::RepeatMode)
-
 }
 }
 
diff --git a/dom/canvas/CanvasRenderingContext2D.h b/dom/canvas/CanvasRenderingContext2D.h
index 144800df77f..152eaf0cdd3 100644
--- a/dom/canvas/CanvasRenderingContext2D.h
+++ b/dom/canvas/CanvasRenderingContext2D.h
@@ -543,17 +543,17 @@ public:
 
   NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS(CanvasRenderingContext2D)
 
-  MOZ_BEGIN_NESTED_ENUM_CLASS(CanvasMultiGetterType, uint8_t)
+  enum class CanvasMultiGetterType : uint8_t {
     STRING = 0,
     PATTERN = 1,
     GRADIENT = 2
-  MOZ_END_NESTED_ENUM_CLASS(CanvasMultiGetterType)
+  };
 
-  MOZ_BEGIN_NESTED_ENUM_CLASS(Style, uint8_t)
+  enum class Style : uint8_t {
     STROKE = 0,
     FILL,
     MAX
-  MOZ_END_NESTED_ENUM_CLASS(Style)
+  };
 
   nsINode* GetParentObject()
   {
@@ -891,31 +891,29 @@ protected:
 
   // text
 
-public: // These enums are public only to accomodate non-C++11 legacy path of
-        // MOZ_FINISH_NESTED_ENUM_CLASS. Can move back to protected as soon
-        // as that legacy path is dropped.
-  MOZ_BEGIN_NESTED_ENUM_CLASS(TextAlign, uint8_t)
+protected:
+  enum class TextAlign : uint8_t {
     START,
     END,
     LEFT,
     RIGHT,
     CENTER
-  MOZ_END_NESTED_ENUM_CLASS(TextAlign)
+  };
 
-  MOZ_BEGIN_NESTED_ENUM_CLASS(TextBaseline, uint8_t)
+  enum class TextBaseline : uint8_t {
     TOP,
     HANGING,
     MIDDLE,
     ALPHABETIC,
     IDEOGRAPHIC,
     BOTTOM
-  MOZ_END_NESTED_ENUM_CLASS(TextBaseline)
+  };
 
-  MOZ_BEGIN_NESTED_ENUM_CLASS(TextDrawOperation, uint8_t)
+  enum class TextDrawOperation : uint8_t {
     FILL,
     STROKE,
     MEASURE
-  MOZ_END_NESTED_ENUM_CLASS(TextDrawOperation)
+  };
 
 protected:
   gfxFontGroup *GetCurrentFontStyle();
@@ -1104,12 +1102,6 @@ protected:
   friend class CanvasDrawObserver;
 };
 
-MOZ_FINISH_NESTED_ENUM_CLASS(CanvasRenderingContext2D::CanvasMultiGetterType)
-MOZ_FINISH_NESTED_ENUM_CLASS(CanvasRenderingContext2D::Style)
-MOZ_FINISH_NESTED_ENUM_CLASS(CanvasRenderingContext2D::TextAlign)
-MOZ_FINISH_NESTED_ENUM_CLASS(CanvasRenderingContext2D::TextBaseline)
-MOZ_FINISH_NESTED_ENUM_CLASS(CanvasRenderingContext2D::TextDrawOperation)
-
 }
 }
 
diff --git a/dom/canvas/WebGLTexelConversions.cpp b/dom/canvas/WebGLTexelConversions.cpp
index 99b177e6bfb..84be38c30d0 100644
--- a/dom/canvas/WebGLTexelConversions.cpp
+++ b/dom/canvas/WebGLTexelConversions.cpp
@@ -37,7 +37,7 @@ class WebGLImageConverter
      * texels with typed pointers and this value will tell us by how much we need
      * to increment these pointers to advance to the next texel.
      */
-    template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) Format>
+    template<WebGLTexelFormat Format>
     static size_t NumElementsPerTexelForFormat() {
         switch (Format) {
             case WebGLTexelFormat::R8:
@@ -78,9 +78,9 @@ class WebGLImageConverter
      * to return immediately in these cases to allow the compiler to avoid generating
      * useless code.
      */
-    template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) SrcFormat,
-             MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) DstFormat,
-             MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelPremultiplicationOp) PremultiplicationOp>
+    template<WebGLTexelFormat SrcFormat,
+             WebGLTexelFormat DstFormat,
+             WebGLTexelPremultiplicationOp PremultiplicationOp>
     void run()
     {
         // check for never-called cases. We early-return to allow the compiler
@@ -151,9 +151,9 @@ class WebGLImageConverter
             typename DataTypeForFormat<DstFormat>::Type
             DstType;
 
-        const MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) IntermediateSrcFormat
+        const WebGLTexelFormat IntermediateSrcFormat
             = IntermediateFormat<SrcFormat>::Value;
-        const MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) IntermediateDstFormat
+        const WebGLTexelFormat IntermediateDstFormat
             = IntermediateFormat<DstFormat>::Value;
         typedef
             typename DataTypeForFormat<IntermediateSrcFormat>::Type
@@ -218,8 +218,8 @@ class WebGLImageConverter
         return;
     }
 
-    template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) SrcFormat,
-             MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) DstFormat>
+    template<WebGLTexelFormat SrcFormat,
+             WebGLTexelFormat DstFormat>
     void run(WebGLTexelPremultiplicationOp premultiplicationOp)
     {
         #define WEBGLIMAGECONVERTER_CASE_PREMULTIPLICATIONOP(PremultiplicationOp) \
@@ -237,7 +237,7 @@ class WebGLImageConverter
         #undef WEBGLIMAGECONVERTER_CASE_PREMULTIPLICATIONOP
     }
 
-    template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) SrcFormat>
+    template<WebGLTexelFormat SrcFormat>
     void run(WebGLTexelFormat dstFormat,
              WebGLTexelPremultiplicationOp premultiplicationOp)
     {
diff --git a/dom/canvas/WebGLTexelConversions.h b/dom/canvas/WebGLTexelConversions.h
index 97a4f5b60d5..813b1e8c0b7 100644
--- a/dom/canvas/WebGLTexelConversions.h
+++ b/dom/canvas/WebGLTexelConversions.h
@@ -155,7 +155,7 @@ enum class WebGLTexelPremultiplicationOp : int {
 
 namespace WebGLTexelConversions {
 
-template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) Format>
+template<WebGLTexelFormat Format>
 struct IsFloatFormat
 {
     static const bool Value =
@@ -166,7 +166,7 @@ struct IsFloatFormat
         Format == WebGLTexelFormat::A32F;
 };
 
-template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) Format>
+template<WebGLTexelFormat Format>
 struct IsHalfFloatFormat
 {
     static const bool Value =
@@ -177,7 +177,7 @@ struct IsHalfFloatFormat
         Format == WebGLTexelFormat::A16F;
 };
 
-template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) Format>
+template<WebGLTexelFormat Format>
 struct Is16bppFormat
 {
     static const bool Value =
@@ -186,7 +186,7 @@ struct Is16bppFormat
         Format == WebGLTexelFormat::RGB565;
 };
 
-template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) Format,
+template<WebGLTexelFormat Format,
          bool IsFloat = IsFloatFormat<Format>::Value,
          bool Is16bpp = Is16bppFormat<Format>::Value,
          bool IsHalfFloat = IsHalfFloatFormat<Format>::Value>
@@ -195,28 +195,28 @@ struct DataTypeForFormat
     typedef uint8_t Type;
 };
 
-template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) Format>
+template<WebGLTexelFormat Format>
 struct DataTypeForFormat<Format, true, false, false>
 {
     typedef float Type;
 };
 
-template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) Format>
+template<WebGLTexelFormat Format>
 struct DataTypeForFormat<Format, false, true, false>
 {
     typedef uint16_t Type;
 };
 
-template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) Format>
+template<WebGLTexelFormat Format>
 struct DataTypeForFormat<Format, false, false, true>
 {
     typedef uint16_t Type;
 };
 
-template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) Format>
+template<WebGLTexelFormat Format>
 struct IntermediateFormat
 {
-    static const MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) Value
+    static const WebGLTexelFormat Value
         = IsFloatFormat<Format>::Value
           ? WebGLTexelFormat::RGBA32F
           : IsHalfFloatFormat<Format>::Value ? WebGLTexelFormat::RGBA16F
@@ -332,7 +332,7 @@ MOZ_ALWAYS_INLINE bool HasColor(WebGLTexelFormat format) {
 //----------------------------------------------------------------------
 // Pixel unpacking routines.
 
-template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) Format, typename SrcType, typename DstType>
+template<WebGLTexelFormat Format, typename SrcType, typename DstType>
 MOZ_ALWAYS_INLINE void
 unpack(const SrcType* __restrict src,
        DstType* __restrict dst)
@@ -537,8 +537,8 @@ unpack<WebGLTexelFormat::A16F, uint16_t, uint16_t>(const uint16_t* __restrict sr
 // Pixel packing routines.
 //
 
-template<MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelFormat) Format,
-         MOZ_ENUM_CLASS_ENUM_TYPE(WebGLTexelPremultiplicationOp) PremultiplicationOp,
+template<WebGLTexelFormat Format,
+         WebGLTexelPremultiplicationOp PremultiplicationOp,
          typename SrcType,
          typename DstType>
 MOZ_ALWAYS_INLINE void
diff --git a/dom/media/MediaDecoderStateMachine.h b/dom/media/MediaDecoderStateMachine.h
index 5b463de0e21..002cae06729 100644
--- a/dom/media/MediaDecoderStateMachine.h
+++ b/dom/media/MediaDecoderStateMachine.h
@@ -1025,11 +1025,11 @@ protected:
   bool mIsAudioPrerolling;
   bool mIsVideoPrerolling;
 
-  MOZ_BEGIN_NESTED_ENUM_CLASS(RequestStatus)
+  enum class RequestStatus {
     Idle,
     Pending,
     Waiting
-  MOZ_END_NESTED_ENUM_CLASS(RequestStatus)
+  };
 
   // True when we have dispatched a task to the decode task queue to request
   // decoded audio/video, and/or we are waiting for the requested sample to be
diff --git a/gfx/ipc/GfxMessageUtils.h b/gfx/ipc/GfxMessageUtils.h
index 114857693c7..6fed7a627ec 100644
--- a/gfx/ipc/GfxMessageUtils.h
+++ b/gfx/ipc/GfxMessageUtils.h
@@ -198,7 +198,7 @@ struct ParamTraits<gfxRect>
 
 template <>
 struct ParamTraits<gfxContentType>
-  : public ContiguousTypedEnumSerializer<
+  : public ContiguousEnumSerializer<
              gfxContentType,
              gfxContentType::COLOR,
              gfxContentType::SENTINEL>
@@ -206,7 +206,7 @@ struct ParamTraits<gfxContentType>
 
 template <>
 struct ParamTraits<gfxSurfaceType>
-  : public ContiguousTypedEnumSerializer<
+  : public ContiguousEnumSerializer<
              gfxSurfaceType,
              gfxSurfaceType::Image,
              gfxSurfaceType::Max>
@@ -222,7 +222,7 @@ struct ParamTraits<mozilla::GraphicsFilterType>
 
 template <>
 struct ParamTraits<mozilla::layers::LayersBackend>
-  : public ContiguousTypedEnumSerializer<
+  : public ContiguousEnumSerializer<
              mozilla::layers::LayersBackend,
              mozilla::layers::LayersBackend::LAYERS_NONE,
              mozilla::layers::LayersBackend::LAYERS_LAST>
@@ -230,7 +230,7 @@ struct ParamTraits<mozilla::layers::LayersBackend>
 
 template <>
 struct ParamTraits<mozilla::layers::ScaleMode>
-  : public ContiguousTypedEnumSerializer<
+  : public ContiguousEnumSerializer<
              mozilla::layers::ScaleMode,
              mozilla::layers::ScaleMode::SCALE_NONE,
              mozilla::layers::ScaleMode::SENTINEL>
@@ -238,7 +238,7 @@ struct ParamTraits<mozilla::layers::ScaleMode>
 
 template <>
 struct ParamTraits<gfxImageFormat>
-  : public ContiguousTypedEnumSerializer<
+  : public ContiguousEnumSerializer<
              gfxImageFormat,
              gfxImageFormat::ARGB32,
              gfxImageFormat::Unknown>
@@ -254,7 +254,7 @@ struct ParamTraits<mozilla::gfx::AttributeName>
 
 template <>
 struct ParamTraits<mozilla::gfx::AttributeType>
-  : public ContiguousTypedEnumSerializer<
+  : public ContiguousEnumSerializer<
              mozilla::gfx::AttributeType,
              mozilla::gfx::AttributeType::eBool,
              mozilla::gfx::AttributeType::Max>
@@ -262,7 +262,7 @@ struct ParamTraits<mozilla::gfx::AttributeType>
 
 template <>
 struct ParamTraits<mozilla::gfx::PrimitiveType>
-  : public ContiguousTypedEnumSerializer<
+  : public ContiguousEnumSerializer<
              mozilla::gfx::PrimitiveType,
              mozilla::gfx::PrimitiveType::Empty,
              mozilla::gfx::PrimitiveType::Max>
@@ -270,7 +270,7 @@ struct ParamTraits<mozilla::gfx::PrimitiveType>
 
 template <>
 struct ParamTraits<mozilla::gfx::ColorSpace>
-  : public ContiguousTypedEnumSerializer<
+  : public ContiguousEnumSerializer<
              mozilla::gfx::ColorSpace,
              mozilla::gfx::ColorSpace::SRGB,
              mozilla::gfx::ColorSpace::Max>
@@ -278,14 +278,14 @@ struct ParamTraits<mozilla::gfx::ColorSpace>
 
 template <>
 struct ParamTraits<mozilla::layers::TextureFlags>
-  : public BitFlagsTypedEnumSerializer<
+  : public BitFlagsEnumSerializer<
             mozilla::layers::TextureFlags,
             mozilla::layers::TextureFlags::ALL_BITS>
 {};
 
 template <>
 struct ParamTraits<mozilla::layers::TextureIdentifier>
-  : public ContiguousTypedEnumSerializer<
+  : public ContiguousEnumSerializer<
              mozilla::layers::TextureIdentifier,
              mozilla::layers::TextureIdentifier::Front,
              mozilla::layers::TextureIdentifier::HighBound>
@@ -293,14 +293,14 @@ struct ParamTraits<mozilla::layers::TextureIdentifier>
 
 template <>
 struct ParamTraits<mozilla::layers::DeprecatedTextureHostFlags>
-  : public BitFlagsTypedEnumSerializer<
+  : public BitFlagsEnumSerializer<
              mozilla::layers::DeprecatedTextureHostFlags,
              mozilla::layers::DeprecatedTextureHostFlags::ALL_BITS>
 {};
 
 template <>
 struct ParamTraits<mozilla::layers::DiagnosticTypes>
-  : public BitFlagsTypedEnumSerializer<
+  : public BitFlagsEnumSerializer<
              mozilla::layers::DiagnosticTypes,
              mozilla::layers::DiagnosticTypes::ALL_BITS>
 {};
@@ -854,7 +854,7 @@ struct ParamTraits<mozilla::layers::TextureInfo>
 
 template <>
 struct ParamTraits<mozilla::layers::CompositableType>
-  : public ContiguousTypedEnumSerializer<
+  : public ContiguousEnumSerializer<
              mozilla::layers::CompositableType,
              mozilla::layers::CompositableType::UNKNOWN,
              mozilla::layers::CompositableType::COUNT>
@@ -862,7 +862,7 @@ struct ParamTraits<mozilla::layers::CompositableType>
 
 template <>
 struct ParamTraits<mozilla::gfx::SurfaceFormat>
-  : public ContiguousTypedEnumSerializer<
+  : public ContiguousEnumSerializer<
              mozilla::gfx::SurfaceFormat,
              mozilla::gfx::SurfaceFormat::B8G8R8A8,
              mozilla::gfx::SurfaceFormat::UNKNOWN>
diff --git a/gfx/layers/client/TextureClient.h b/gfx/layers/client/TextureClient.h
index e52d9ad0754..c5097186266 100644
--- a/gfx/layers/client/TextureClient.h
+++ b/gfx/layers/client/TextureClient.h
@@ -89,9 +89,9 @@ public:
 
   static TemporaryRef<SyncObject> CreateSyncObject(SyncHandle aHandle);
 
-  MOZ_BEGIN_NESTED_ENUM_CLASS(SyncType)
+  enum class SyncType {
     D3D11,
-  MOZ_END_NESTED_ENUM_CLASS(SyncType)
+  };
 
   virtual SyncType GetSyncType() = 0;
   virtual void FinalizeFrame() = 0;
diff --git a/gfx/thebes/gfxPrefs.h b/gfx/thebes/gfxPrefs.h
index 3271af05dc8..47c89cf828d 100644
--- a/gfx/thebes/gfxPrefs.h
+++ b/gfx/thebes/gfxPrefs.h
@@ -78,14 +78,14 @@ private:
 
 private:
   // Enums for the update policy.
-  MOZ_BEGIN_NESTED_ENUM_CLASS(UpdatePolicy)
+  enum class UpdatePolicy {
     Skip, // Set the value to default, skip any Preferences calls
     Once, // Evaluate the preference once, unchanged during the session
     Live  // Evaluate the preference and set callback so it stays current/live
-  MOZ_END_NESTED_ENUM_CLASS(UpdatePolicy)
+  };
 
   // Since we cannot use const char*, use a function that returns it.
-  template <MOZ_ENUM_CLASS_ENUM_TYPE(UpdatePolicy) Update, class T, T Default(void), const char* Pref(void)>
+  template <UpdatePolicy Update, class T, T Default(void), const char* Pref(void)>
   class PrefTemplate
   {
   public:
diff --git a/ipc/glue/IPCMessageUtils.h b/ipc/glue/IPCMessageUtils.h
index 60336217fa0..02ecc742149 100644
--- a/ipc/glue/IPCMessageUtils.h
+++ b/ipc/glue/IPCMessageUtils.h
@@ -129,18 +129,7 @@ struct EnumSerializer {
 template <typename E,
           E MinLegal,
           E HighBound>
-struct ContiguousEnumValidator
-{
-  static bool IsLegalValue(E e)
-  {
-    return MinLegal <= e && e < HighBound;
-  }
-};
-
-template <typename E,
-          MOZ_TEMPLATE_ENUM_CLASS_ENUM_TYPE(E) MinLegal,
-          MOZ_TEMPLATE_ENUM_CLASS_ENUM_TYPE(E) HighBound>
-class ContiguousTypedEnumValidator
+class ContiguousEnumValidator
 {
   // Silence overzealous -Wtype-limits bug in GCC fixed in GCC 4.8:
   // "comparison of unsigned expression >= 0 is always true"
@@ -151,9 +140,7 @@ class ContiguousTypedEnumValidator
 public:
   static bool IsLegalValue(E e)
   {
-    typedef MOZ_TEMPLATE_ENUM_CLASS_ENUM_TYPE(E) ActualEnumType;
-    return IsLessThanOrEqual(MinLegal, ActualEnumType(e)) &&
-           ActualEnumType(e) < HighBound;
+    return IsLessThanOrEqual(MinLegal, e) && e < HighBound;
   }
 };
 
@@ -167,16 +154,6 @@ struct BitFlagsEnumValidator
   }
 };
 
-template <typename E,
-          MOZ_TEMPLATE_ENUM_CLASS_ENUM_TYPE(E) AllBits>
-struct BitFlagsTypedEnumValidator
-{
-  static bool IsLegalValue(E e)
-  {
-    return (e & AllBits) == e;
-  }
-};
-
 /**
  * Specialization of EnumSerializer for enums with contiguous enum values.
  *
@@ -201,19 +178,6 @@ struct ContiguousEnumSerializer
                    ContiguousEnumValidator<E, MinLegal, HighBound>>
 {};
 
-/**
- * Similar to ContiguousEnumSerializer, but for MFBT typed enums
- * as constructed by MOZ_BEGIN_ENUM_CLASS. This can go away when
- * we drop MOZ_BEGIN_ENUM_CLASS and use C++11 enum classes directly.
- */
-template <typename E,
-          MOZ_TEMPLATE_ENUM_CLASS_ENUM_TYPE(E) MinLegal,
-          MOZ_TEMPLATE_ENUM_CLASS_ENUM_TYPE(E) HighBound>
-struct ContiguousTypedEnumSerializer
-  : EnumSerializer<E,
-                   ContiguousTypedEnumValidator<E, MinLegal, HighBound>>
-{};
-
 /**
  * Specialization of EnumSerializer for enums representing bit flags.
  *
@@ -241,18 +205,6 @@ struct BitFlagsEnumSerializer
                    BitFlagsEnumValidator<E, AllBits>>
 {};
 
-/**
- * Similar to BitFlagsEnumSerializer, but for MFBT typed enums
- * as constructed by MOZ_BEGIN_ENUM_CLASS. This can go away when
- * we drop MOZ_BEGIN_ENUM_CLASS and use C++11 enum classes directly.
- */
-template <typename E,
-          MOZ_TEMPLATE_ENUM_CLASS_ENUM_TYPE(E) AllBits>
-struct BitFlagsTypedEnumSerializer
-  : EnumSerializer<E,
-                   BitFlagsTypedEnumValidator<E, AllBits>>
-{};
-
 template <>
 struct ParamTraits<base::ChildPrivileges>
   : public ContiguousEnumSerializer<base::ChildPrivileges,
diff --git a/js/public/ProfilingStack.h b/js/public/ProfilingStack.h
index d66eb264f66..0ad78dcdf50 100644
--- a/js/public/ProfilingStack.h
+++ b/js/public/ProfilingStack.h
@@ -73,7 +73,7 @@ class ProfileEntry
     };
 
     // Keep these in sync with browser/devtools/profiler/utils/global.js
-    MOZ_BEGIN_NESTED_ENUM_CLASS(Category, uint32_t)
+    enum class Category : uint32_t {
         OTHER    = 0x10,
         CSS      = 0x20,
         JS       = 0x40,
@@ -86,7 +86,7 @@ class ProfileEntry
 
         FIRST    = OTHER,
         LAST     = EVENTS
-    MOZ_END_NESTED_ENUM_CLASS(Category)
+    };
 
     // All of these methods are marked with the 'volatile' keyword because SPS's
     // representation of the stack is stored such that all ProfileEntry
diff --git a/layout/base/nsLayoutUtils.h b/layout/base/nsLayoutUtils.h
index 5cfac111538..319137e942f 100644
--- a/layout/base/nsLayoutUtils.h
+++ b/layout/base/nsLayoutUtils.h
@@ -163,10 +163,10 @@ public:
    */
   static bool GetDisplayPort(nsIContent* aContent, nsRect *aResult = nullptr);
 
-  MOZ_BEGIN_NESTED_ENUM_CLASS(RepaintMode, uint8_t)
+  enum class RepaintMode : uint8_t {
     Repaint,
     DoNotRepaint
-  MOZ_END_NESTED_ENUM_CLASS(RepaintMode)
+  };
 
   /**
    * Set the display port margins for a content element to be used with a
@@ -2577,8 +2577,6 @@ private:
   static bool IsAPZTestLoggingEnabled();
 };
 
-MOZ_FINISH_NESTED_ENUM_CLASS(nsLayoutUtils::RepaintMode)
-
 template<typename PointType, typename RectType, typename CoordType>
 /* static */ bool
 nsLayoutUtils::PointIsCloserToRect(PointType aPoint, const RectType& aRect,
diff --git a/mfbt/EnumeratedArray.h b/mfbt/EnumeratedArray.h
index 470d5f5e8d1..daac9b08629 100644
--- a/mfbt/EnumeratedArray.h
+++ b/mfbt/EnumeratedArray.h
@@ -16,8 +16,7 @@ namespace mozilla {
 
 /**
  * EnumeratedArray is a fixed-size array container for use when an
- * array is indexed by a specific enum class, as currently implemented
- * by MOZ_BEGIN_ENUM_CLASS.
+ * array is indexed by a specific enum class.
  *
  * This provides type safety by guarding at compile time against accidentally
  * indexing such arrays with unrelated values. This also removes the need
@@ -40,7 +39,7 @@ namespace mozilla {
  *
  */
 template<typename IndexType,
-         MOZ_TEMPLATE_ENUM_CLASS_ENUM_TYPE(IndexType) SizeAsEnumValue,
+         IndexType SizeAsEnumValue,
          typename ValueType>
 class EnumeratedArray
 {
diff --git a/xpcom/base/CycleCollectedJSRuntime.h b/xpcom/base/CycleCollectedJSRuntime.h
index c3bf60b30c4..0591774f749 100644
--- a/xpcom/base/CycleCollectedJSRuntime.h
+++ b/xpcom/base/CycleCollectedJSRuntime.h
@@ -212,7 +212,7 @@ private:
 public:
   // Two conditions, JSOutOfMemory and JSLargeAllocationFailure, are noted in
   // crash reports. Here are the values that can appear in the reports:
-  MOZ_BEGIN_NESTED_ENUM_CLASS(OOMState, uint32_t)
+  enum class OOMState : uint32_t {
     // The condition has never happened. No entry appears in the crash report.
     OK,
 
@@ -240,7 +240,7 @@ public:
     // GC is taken as a proxy for "we've been banging on the heap a good bit
     // now and haven't crashed; the OOM was probably handled correctly".
     Recovered
-  MOZ_END_NESTED_ENUM_CLASS(OOMState)
+  };
 
 private:
   void AnnotateAndSetOutOfMemory(OOMState* aStatePtr, OOMState aNewState);
@@ -316,8 +316,6 @@ private:
   OOMState mLargeAllocationFailureState;
 };
 
-MOZ_FINISH_NESTED_ENUM_CLASS(CycleCollectedJSRuntime::OOMState)
-
 void TraceScriptHolder(nsISupports* aHolder, JSTracer* aTracer);
 
 // Returns true if the JSGCTraceKind is one the cycle collector cares about.
diff --git a/xpcom/glue/EnumeratedArrayCycleCollection.h b/xpcom/glue/EnumeratedArrayCycleCollection.h
index ac5469a202a..faabb5a529d 100644
--- a/xpcom/glue/EnumeratedArrayCycleCollection.h
+++ b/xpcom/glue/EnumeratedArrayCycleCollection.h
@@ -11,7 +11,7 @@
 #include "nsCycleCollectionTraversalCallback.h"
 
 template<typename IndexType,
-         MOZ_TEMPLATE_ENUM_CLASS_ENUM_TYPE(IndexType) SizeAsEnumValue,
+         IndexType SizeAsEnumValue,
          typename ValueType>
 inline void
 ImplCycleCollectionUnlink(mozilla::EnumeratedArray<IndexType,
@@ -24,7 +24,7 @@ ImplCycleCollectionUnlink(mozilla::EnumeratedArray<IndexType,
 }
 
 template<typename IndexType,
-         MOZ_TEMPLATE_ENUM_CLASS_ENUM_TYPE(IndexType) SizeAsEnumValue,
+         IndexType SizeAsEnumValue,
          typename ValueType>
 inline void
 ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,