diff --git a/accessible/xul/XULFormControlAccessible.cpp b/accessible/xul/XULFormControlAccessible.cpp
index 7005287553ce..c68c8a455a00 100644
--- a/accessible/xul/XULFormControlAccessible.cpp
+++ b/accessible/xul/XULFormControlAccessible.cpp
@@ -16,7 +16,6 @@
 #include "TreeWalker.h"
 #include "XULMenuAccessible.h"
 
-#include "nsIDOMNSEditableElement.h"
 #include "nsIDOMXULButtonElement.h"
 #include "nsIDOMXULCheckboxElement.h"
 #include "nsIDOMXULMenuListElement.h"
diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index a99563875c8f..d65dd301d03e 100644
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -229,7 +229,6 @@
 #include "nsViewportInfo.h"
 #include "mozilla/StaticPtr.h"
 #include "nsITextControlElement.h"
-#include "nsIDOMNSEditableElement.h"
 #include "nsIEditor.h"
 #include "nsIHttpChannelInternal.h"
 #include "nsISecurityConsoleMessage.h"
diff --git a/toolkit/components/satchel/nsFormFillController.cpp b/toolkit/components/satchel/nsFormFillController.cpp
index 4ad428b20a6e..a9d2c08c908e 100644
--- a/toolkit/components/satchel/nsFormFillController.cpp
+++ b/toolkit/components/satchel/nsFormFillController.cpp
@@ -37,7 +37,6 @@
 #include "mozilla/ModuleUtils.h"
 #include "nsToolkitCompsCID.h"
 #include "nsEmbedCID.h"
-#include "nsIDOMNSEditableElement.h"
 #include "nsContentUtils.h"
 #include "nsGenericHTMLElement.h"
 #include "nsILoadContext.h"
diff --git a/toolkit/components/typeaheadfind/nsTypeAheadFind.cpp b/toolkit/components/typeaheadfind/nsTypeAheadFind.cpp
index 0aa2429bbdf8..e01ca28ac5cf 100644
--- a/toolkit/components/typeaheadfind/nsTypeAheadFind.cpp
+++ b/toolkit/components/typeaheadfind/nsTypeAheadFind.cpp
@@ -31,7 +31,6 @@
 #include "nsIDocument.h"
 #include "nsIContent.h"
 #include "nsTextFragment.h"
-#include "nsIDOMNSEditableElement.h"
 #include "nsIEditor.h"
 
 #include "nsIDocShellTreeItem.h"
@@ -47,6 +46,8 @@
 #include "nsIObserverService.h"
 #include "nsFocusManager.h"
 #include "mozilla/dom/Element.h"
+#include "mozilla/dom/HTMLInputElement.h"
+#include "mozilla/dom/HTMLTextAreaElement.h"
 #include "mozilla/dom/Link.h"
 #include "mozilla/dom/RangeBinding.h"
 #include "mozilla/dom/Selection.h"
@@ -576,33 +577,38 @@ nsTypeAheadFind::FindItNow(nsIPresShell *aPresShell, bool aIsLinksOnly,
         // chain of parent nodes to see if we find one.
         nsCOMPtr<nsINode> node = returnRange->GetStartContainer();
         while (node) {
-          nsCOMPtr<nsIDOMNSEditableElement> editable = do_QueryInterface(node);
-          if (editable) {
-            // Inside an editable element.  Get the correct selection
-            // controller and selection.
-            nsCOMPtr<nsIEditor> editor;
-            editable->GetEditor(getter_AddRefs(editor));
-            NS_ASSERTION(editor, "Editable element has no editor!");
-            if (!editor) {
-              break;
-            }
-            editor->GetSelectionController(
-              getter_AddRefs(selectionController));
-            if (selectionController) {
-              selection = selectionController->GetSelection(
-                nsISelectionController::SELECTION_NORMAL);
-            }
-            mFoundEditable = do_QueryInterface(node);
+          nsCOMPtr<nsIEditor> editor;
+          if (auto input = HTMLInputElement::FromNode(node)) {
+            editor = input->GetEditor();
+          } else if (auto textarea = HTMLTextAreaElement::FromNode(node)) {
+            editor = textarea->GetEditor();
+          } else {
+            node = node->GetParentNode();
+            continue;
+          }
 
-            if (!shouldFocusEditableElement)
-              break;
-
-            // Otherwise move focus/caret to editable element
-            if (fm)
-              fm->SetFocus(mFoundEditable, 0);
+          // Inside an editable element.  Get the correct selection
+          // controller and selection.
+          NS_ASSERTION(editor, "Editable element has no editor!");
+          if (!editor) {
             break;
           }
-          node = node->GetParentNode();
+          editor->GetSelectionController(getter_AddRefs(selectionController));
+          if (selectionController) {
+            selection = selectionController->GetSelection(
+              nsISelectionController::SELECTION_NORMAL);
+          }
+          mFoundEditable = node->AsElement();
+
+          if (!shouldFocusEditableElement) {
+            break;
+          }
+
+          // Otherwise move focus/caret to editable element
+          if (fm) {
+            fm->SetFocus(mFoundEditable, 0);
+          }
+          break;
         }
 
         // If we reach here without setting mFoundEditable, then something