--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -1279,32 +1279,32 @@ nsIDocument::nsIDocument()
     mReferrerPolicySet(false),
     mReferrerPolicy(mozilla::net::RP_Unset),
     mBlockAllMixedContent(false),
     mBlockAllMixedContentPreloads(false),
     mUpgradeInsecureRequests(false),
     mUpgradeInsecurePreloads(false),
     mCharacterSet(NS_LITERAL_CSTRING("ISO-8859-1")),
     mNodeInfoManager(nullptr),
-    mCompatMode(eCompatibility_FullStandards),
-    mVisibilityState(dom::VisibilityState::Hidden),
     mIsInitialDocumentInWindow(false),
     mMayStartLayout(true),
     mVisible(true),
     mRemovedFromDocShell(false),
     // mAllowDNSPrefetch starts true, so that we can always reliably && it
     // with various values that might disable it.  Since we never prefetch
     // unless we get a window, and in that case the docshell value will get
     // &&-ed in, this is safe.
     mAllowDNSPrefetch(true),
     mIsBeingUsedAsImage(false),
     mHasLinksToUpdate(false),
     mFontFaceSetDirty(true),
     mGetUserFontSetCalled(false),
     mPostedFlushUserFontSet(false),
+    mCompatMode(eCompatibility_FullStandards),
+    mVisibilityState(dom::VisibilityState::Hidden),
     mBidiOptions(IBMBIDI_DEFAULT_BIDI_OPTIONS),
     mPartID(0),
     mDidFireDOMContentLoaded(true),
     mHasScrollLinkedEffect(false),
     mUserHasInteracted(false)
 {
   SetIsInDocument();
 

--- a/dom/base/nsIDocument.h
+++ b/dom/base/nsIDocument.h
@@ -3027,34 +3027,22 @@ protected:
   nsTArray<nsAutoPtr<nsPropertyTable> > mExtraPropertyTables;
 
   // Our cached .children collection
   nsCOMPtr<nsIHTMLCollection> mChildrenCollection;
 
   // container for per-context fonts (downloadable, SVG, etc.)
   RefPtr<mozilla::dom::FontFaceSet> mFontFaceSet;
 
-  // Compatibility mode
-  nsCompatibility mCompatMode;
-
-  // Our readyState
-  ReadyState mReadyState;
-
-  // Whether this document has (or will have, once we have a pres shell) a
-  // Gecko- or Servo-backed style system.
-  mozilla::StyleBackendType mStyleBackendType;
-
-#ifdef MOZILLA_INTERNAL_API
-  // Our visibility state
-  mozilla::dom::VisibilityState mVisibilityState;
-  static_assert(sizeof(mozilla::dom::VisibilityState) == sizeof(uint8_t),
-                "Error size of mVisibilityState and mDummy");
-#else
-  uint8_t mDummy;
-#endif
+  // XXXheycam rust-bindgen currently doesn't generate correctly aligned fields
+  // to represent the following bitfields if they are preceded by something
+  // non-pointer aligned, so if adding non-pointer sized fields, please do so
+  // somewhere other than right here.
+  //
+  // https://github.com/servo/rust-bindgen/issues/111
 
   // True if BIDI is enabled.
   bool mBidiEnabled : 1;
   // True if a MathML element has ever been owned by this document.
   bool mMathMLEnabled : 1;
 
   // True if this document is the initial document for a window.  This should
   // basically be true only for documents that exist in newly-opened windows or
@@ -3194,16 +3182,35 @@ protected:
   bool mGetUserFontSetCalled : 1;
 
   // Do we currently have an event posted to call FlushUserFontSet?
   bool mPostedFlushUserFontSet : 1;
 
   // True is document has ever been in a foreground window.
   bool mEverInForeground : 1;
 
+  // Compatibility mode
+  nsCompatibility mCompatMode;
+
+  // Our readyState
+  ReadyState mReadyState;
+
+  // Whether this document has (or will have, once we have a pres shell) a
+  // Gecko- or Servo-backed style system.
+  mozilla::StyleBackendType mStyleBackendType;
+
+#ifdef MOZILLA_INTERNAL_API
+  // Our visibility state
+  mozilla::dom::VisibilityState mVisibilityState;
+  static_assert(sizeof(mozilla::dom::VisibilityState) == sizeof(uint8_t),
+                "Error size of mVisibilityState and mDummy");
+#else
+  uint8_t mDummy;
+#endif
+
   enum Type {
     eUnknown, // should never be used
     eHTML,
     eXHTML,
     eGenericXML,
     eSVG,
     eXUL
   };