diff --git a/editor/libeditor/HTMLEditRules.cpp b/editor/libeditor/HTMLEditRules.cpp
index 6d092b06b4f0..14a5c73cef7c 100644
--- a/editor/libeditor/HTMLEditRules.cpp
+++ b/editor/libeditor/HTMLEditRules.cpp
@@ -16,13 +16,14 @@
 #include "mozilla/EditorUtils.h"
 #include "mozilla/HTMLEditor.h"
 #include "mozilla/MathAlgorithms.h"
+#include "mozilla/Move.h"
 #include "mozilla/Preferences.h"
+#include "mozilla/UniquePtr.h"
 #include "mozilla/Unused.h"
 #include "mozilla/dom/Selection.h"
 #include "mozilla/dom/Element.h"
 #include "mozilla/OwningNonNull.h"
 #include "mozilla/mozalloc.h"
-#include "nsAutoPtr.h"
 #include "nsAString.h"
 #include "nsAlgorithm.h"
 #include "nsCRT.h"
@@ -4499,20 +4500,21 @@ HTMLEditRules::CreateStyleForInsertText(Selection& aSelection,
   NS_ENSURE_STATE(rootElement);
 
   // process clearing any styles first
-  nsAutoPtr<PropItem> item(mHTMLEditor->mTypeInState->TakeClearProperty());
+  UniquePtr<PropItem> item =
+    Move(mHTMLEditor->mTypeInState->TakeClearProperty());
   while (item && node != rootElement) {
     NS_ENSURE_STATE(mHTMLEditor);
     nsresult rv =
       mHTMLEditor->ClearStyle(address_of(node), &offset,
                               item->tag, &item->attr);
     NS_ENSURE_SUCCESS(rv, rv);
-    item = mHTMLEditor->mTypeInState->TakeClearProperty();
+    item = Move(mHTMLEditor->mTypeInState->TakeClearProperty());
     weDidSomething = true;
   }
 
   // then process setting any styles
   int32_t relFontSize = mHTMLEditor->mTypeInState->TakeRelativeFontSize();
-  item = mHTMLEditor->mTypeInState->TakeSetProperty();
+  item = Move(mHTMLEditor->mTypeInState->TakeSetProperty());
 
   if (item || relFontSize) {
     // we have at least one style to add; make a new text node to insert style
diff --git a/editor/libeditor/TypeInState.cpp b/editor/libeditor/TypeInState.cpp
index ce43e5e4dc6d..840139feeddb 100644
--- a/editor/libeditor/TypeInState.cpp
+++ b/editor/libeditor/TypeInState.cpp
@@ -193,7 +193,7 @@ TypeInState::ClearProp(nsIAtom* aProp,
  * TakeClearProperty() hands back next property item on the clear list.
  * Caller assumes ownership of PropItem and must delete it.
  */
-PropItem*
+UniquePtr<PropItem>
 TypeInState::TakeClearProperty()
 {
   size_t count = mClearedArray.Length();
@@ -204,14 +204,14 @@ TypeInState::TakeClearProperty()
   --count; // indices are zero based
   PropItem* propItem = mClearedArray[count];
   mClearedArray.RemoveElementAt(count);
-  return propItem;
+  return UniquePtr<PropItem>(propItem);
 }
 
 /**
  * TakeSetProperty() hands back next poroperty item on the set list.
  * Caller assumes ownership of PropItem and must delete it.
  */
-PropItem*
+UniquePtr<PropItem>
 TypeInState::TakeSetProperty()
 {
   size_t count = mSetArray.Length();
@@ -221,7 +221,7 @@ TypeInState::TakeSetProperty()
   count--; // indices are zero based
   PropItem* propItem = mSetArray[count];
   mSetArray.RemoveElementAt(count);
-  return propItem;
+  return UniquePtr<PropItem>(propItem);
 }
 
 /**
diff --git a/editor/libeditor/TypeInState.h b/editor/libeditor/TypeInState.h
index 540b2d9c1194..e1b949508c22 100644
--- a/editor/libeditor/TypeInState.h
+++ b/editor/libeditor/TypeInState.h
@@ -6,6 +6,7 @@
 #ifndef TypeInState_h
 #define TypeInState_h
 
+#include "mozilla/UniquePtr.h"
 #include "nsCOMPtr.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsISelectionListener.h"
@@ -63,13 +64,13 @@ public:
    * TakeClearProperty() hands back next property item on the clear list.
    * Caller assumes ownership of PropItem and must delete it.
    */
-  PropItem* TakeClearProperty();
+  UniquePtr<PropItem> TakeClearProperty();
 
   /**
    * TakeSetProperty() hands back next property item on the set list.
    * Caller assumes ownership of PropItem and must delete it.
    */
-  PropItem* TakeSetProperty();
+  UniquePtr<PropItem> TakeSetProperty();
 
   /**
    * TakeRelativeFontSize() hands back relative font value, which is then