diff --git a/gfx/thebes/gfxFont.cpp b/gfx/thebes/gfxFont.cpp
index ff8dedf13ec5..dbf1128608eb 100644
--- a/gfx/thebes/gfxFont.cpp
+++ b/gfx/thebes/gfxFont.cpp
@@ -6293,7 +6293,7 @@ gfxTextRun::BreakAndMeasureText(uint32_t aStart, uint32_t aMaxLength,
             bool hyphenation = haveHyphenation && hyphenBuffer[i - bufferStart];
             bool wordWrapping =
                 aCanWordWrap && mCharacterGlyphs[i].IsClusterStart() &&
-                *aBreakPriority <= eWordWrapBreak;
+                *aBreakPriority <= gfxBreakPriority::eWordWrapBreak;
 
             if (lineBreakHere || hyphenation || wordWrapping) {
                 gfxFloat hyphenatedAdvance = advance;
@@ -6308,7 +6308,7 @@ gfxTextRun::BreakAndMeasureText(uint32_t aStart, uint32_t aMaxLength,
                     lastBreakTrimmableAdvance = trimmableAdvance;
                     lastBreakUsedHyphenation = !lineBreakHere && !wordWrapping;
                     *aBreakPriority = hyphenation || lineBreakHere ?
-                        eNormalBreak : eWordWrapBreak;
+                        gfxBreakPriority::eNormalBreak : gfxBreakPriority::eWordWrapBreak;
                 }
 
                 width += advance;
diff --git a/gfx/thebes/gfxTypes.h b/gfx/thebes/gfxTypes.h
index c82d01cafd5b..2b92383e1f2c 100644
--- a/gfx/thebes/gfxTypes.h
+++ b/gfx/thebes/gfxTypes.h
@@ -6,6 +6,9 @@
 #ifndef GFX_TYPES_H
 #define GFX_TYPES_H
 
+#include <stdint.h>
+#include "mozilla/TypedEnum.h"
+
 typedef struct _cairo_surface cairo_surface_t;
 typedef struct _cairo_user_data_key cairo_user_data_key_t;
 
@@ -36,11 +39,11 @@ typedef double gfxFloat;
  * @see gfxTextRun::BreakAndMeasureText
  * @see nsLineLayout::NotifyOptionalBreakPosition
  */
-enum gfxBreakPriority {
-    eNoBreak       = 0,
-    eWordWrapBreak,
-    eNormalBreak
-};
+MOZ_BEGIN_ENUM_CLASS(gfxBreakPriority)
+  eNoBreak       = 0,
+  eWordWrapBreak,
+  eNormalBreak
+MOZ_END_ENUM_CLASS(gfxBreakPriority)
 
     /**
      * The format for an image surface. For all formats with alpha data, 0
diff --git a/layout/generic/nsBlockFrame.cpp b/layout/generic/nsBlockFrame.cpp
index ca74e39abb0f..307103db6395 100644
--- a/layout/generic/nsBlockFrame.cpp
+++ b/layout/generic/nsBlockFrame.cpp
@@ -3346,7 +3346,7 @@ nsBlockFrame::ReflowInlineFrames(nsBlockReflowState& aState,
       bool allowPullUp = true;
       nsIContent* forceBreakInContent = nullptr;
       int32_t forceBreakOffset = -1;
-      gfxBreakPriority forceBreakPriority = eNoBreak;
+      gfxBreakPriority forceBreakPriority = gfxBreakPriority::eNoBreak;
       do {
         nsFloatManager::SavedState floatManagerState;
         aState.mReflowState.mFloatManager->PushState(&floatManagerState);
@@ -3498,7 +3498,7 @@ nsBlockFrame::DoReflowInlineFrames(nsBlockReflowState& aState,
   if (aFloatAvailableSpace.mHasFloats) {
     // There is a soft break opportunity at the start of the line, because
     // we can always move this line down below float(s).
-    if (aLineLayout.NotifyOptionalBreakPosition(frame->GetContent(), 0, true, eNormalBreak)) {
+    if (aLineLayout.NotifyOptionalBreakPosition(frame->GetContent(), 0, true, gfxBreakPriority::eNormalBreak)) {
       lineReflowStatus = LINE_REFLOW_REDO_NEXT_BAND;
     }
   }
diff --git a/layout/generic/nsLineLayout.cpp b/layout/generic/nsLineLayout.cpp
index 79d314c0602e..5095ae308084 100644
--- a/layout/generic/nsLineLayout.cpp
+++ b/layout/generic/nsLineLayout.cpp
@@ -57,7 +57,7 @@ nsLineLayout::nsLineLayout(nsPresContext* aPresContext,
     mLastOptionalBreakContent(nullptr),
     mForceBreakContent(nullptr),
     mBlockRS(nullptr),/* XXX temporary */
-    mLastOptionalBreakPriority(eNoBreak),
+    mLastOptionalBreakPriority(gfxBreakPriority::eNoBreak),
     mLastOptionalBreakContentOffset(-1),
     mForceBreakContentOffset(-1),
     mMinLineHeight(0),
@@ -1025,7 +1025,7 @@ nsLineLayout::ReflowFrame(nsIFrame* aFrame,
           // record soft break opportunity after this content that can't be
           // part of a text run. This is not a text frame so we know
           // that offset INT32_MAX means "after the content".
-          if (NotifyOptionalBreakPosition(aFrame->GetContent(), INT32_MAX, optionalBreakAfterFits, eNormalBreak)) {
+          if (NotifyOptionalBreakPosition(aFrame->GetContent(), INT32_MAX, optionalBreakAfterFits, gfxBreakPriority::eNormalBreak)) {
             // If this returns true then we are being told to actually break here.
             aReflowStatus = NS_INLINE_LINE_BREAK_AFTER(aReflowStatus);
           }
diff --git a/layout/generic/nsLineLayout.h b/layout/generic/nsLineLayout.h
index ecb3e996558a..0d8c1e2fea67 100644
--- a/layout/generic/nsLineLayout.h
+++ b/layout/generic/nsLineLayout.h
@@ -247,7 +247,7 @@ public:
     mNeedBackup = false;
     mLastOptionalBreakContent = nullptr;
     mLastOptionalBreakContentOffset = -1;
-    mLastOptionalBreakPriority = eNoBreak;
+    mLastOptionalBreakPriority = gfxBreakPriority::eNoBreak;
   }
   // Retrieve last set optional break position. When this returns null, no
   // optional break has been recorded (which means that the line can't break yet).
diff --git a/layout/generic/nsTextFrame.cpp b/layout/generic/nsTextFrame.cpp
index a750cf0fa47b..6538b01f22bc 100644
--- a/layout/generic/nsTextFrame.cpp
+++ b/layout/generic/nsTextFrame.cpp
@@ -8092,7 +8092,7 @@ nsTextFrame::ReflowText(nsLineLayout& aLineLayout, nscoord aAvailableWidth,
     // Record a potential break after final soft hyphen
     aLineLayout.NotifyOptionalBreakPosition(mContent, offset + length,
         textMetrics.mAdvanceWidth + provider.GetHyphenWidth() <= availWidth,
-                                           eNormalBreak);
+                                           gfxBreakPriority::eNormalBreak);
   }
   bool breakAfter = forceBreakAfter;
   // length == 0 means either the text is empty or it's all collapsed away
@@ -8112,7 +8112,7 @@ nsTextFrame::ReflowText(nsLineLayout& aLineLayout, nscoord aAvailableWidth,
       breakAfter = true;
     } else {
       aLineLayout.NotifyOptionalBreakPosition(mContent, offset + length,
-                                              true, eNormalBreak);
+                                              true, gfxBreakPriority::eNormalBreak);
     }
   }