diff --git a/editor/libeditor/html/nsHTMLCSSUtils.cpp b/editor/libeditor/html/nsHTMLCSSUtils.cpp
index c044d4c731f5..4b1ce734b5a9 100644
--- a/editor/libeditor/html/nsHTMLCSSUtils.cpp
+++ b/editor/libeditor/html/nsHTMLCSSUtils.cpp
@@ -964,7 +964,22 @@ nsHTMLCSSUtils::RemoveCSSEquivalentToHTMLStyle(nsIDOMNode * aNode,
                                                bool aSuppressTransaction)
 {
   nsCOMPtr<dom::Element> element = do_QueryInterface(aNode);
-  if (!element || !IsCSSEditableProperty(element, aHTMLProperty, aAttribute)) {
+  NS_ENSURE_TRUE(element, NS_OK);
+
+  return RemoveCSSEquivalentToHTMLStyle(element, aHTMLProperty, aAttribute,
+                                        aValue, aSuppressTransaction);
+}
+
+nsresult
+nsHTMLCSSUtils::RemoveCSSEquivalentToHTMLStyle(dom::Element* aElement,
+                                               nsIAtom* aHTMLProperty,
+                                               const nsAString* aAttribute,
+                                               const nsAString* aValue,
+                                               bool aSuppressTransaction)
+{
+  MOZ_ASSERT(aElement);
+
+  if (!IsCSSEditableProperty(aElement, aHTMLProperty, aAttribute)) {
     return NS_OK;
   }
 
@@ -974,11 +989,11 @@ nsHTMLCSSUtils::RemoveCSSEquivalentToHTMLStyle(nsIDOMNode * aNode,
   // Find the CSS equivalence to the HTML style
   nsTArray<nsIAtom*> cssPropertyArray;
   nsTArray<nsString> cssValueArray;
-  GenerateCSSDeclarationsFromHTMLStyle(element, aHTMLProperty, aAttribute,
+  GenerateCSSDeclarationsFromHTMLStyle(aElement, aHTMLProperty, aAttribute,
                                        aValue, cssPropertyArray, cssValueArray,
                                        true);
 
-  nsCOMPtr<nsIDOMElement> domElement = do_QueryInterface(element);
+  nsCOMPtr<nsIDOMElement> domElement = do_QueryInterface(aElement);
   // remove the individual CSS inline styles
   int32_t count = cssPropertyArray.Length();
   for (int32_t index = 0; index < count; index++) {
diff --git a/editor/libeditor/html/nsHTMLCSSUtils.h b/editor/libeditor/html/nsHTMLCSSUtils.h
index 7ce042c42606..7bc47a0e3266 100644
--- a/editor/libeditor/html/nsHTMLCSSUtils.h
+++ b/editor/libeditor/html/nsHTMLCSSUtils.h
@@ -239,6 +239,20 @@ public:
                                              const nsAString *aAttribute,
                                              const nsAString *aValue,
                                              bool aSuppressTransaction);
+  /** removes from the node the CSS inline styles equivalent to the HTML style
+    *
+    * @param aElement       [IN] a DOM Element (must not be null)
+    * @param aHTMLProperty  [IN] an atom containing an HTML property
+    * @param aAttribute     [IN] a pointer to an attribute name or nullptr if irrelevant
+    * @param aValue         [IN] the attribute value
+    * @param aSuppressTransaction [IN] a boolean indicating, when true,
+    *                                  that no transaction should be recorded
+    */
+  nsresult    RemoveCSSEquivalentToHTMLStyle(mozilla::dom::Element* aElement,
+                                             nsIAtom* aHTMLProperty,
+                                             const nsAString* aAttribute,
+                                             const nsAString* aValue,
+                                             bool aSuppressTransaction);
 
   /** parses a "xxxx.xxxxxuuu" string where x is a digit and u an alpha char
     * we need such a parser because nsIDOMCSSStyleDeclaration::GetPropertyCSSValue() is not
diff --git a/editor/libeditor/html/nsHTMLEditor.cpp b/editor/libeditor/html/nsHTMLEditor.cpp
index dfcf318fa8ac..6ea58774d775 100644
--- a/editor/libeditor/html/nsHTMLEditor.cpp
+++ b/editor/libeditor/html/nsHTMLEditor.cpp
@@ -4579,26 +4579,30 @@ nsHTMLEditor::SetAttributeOrEquivalent(nsIDOMElement * aElement,
 }
 
 nsresult
-nsHTMLEditor::RemoveAttributeOrEquivalent(nsIDOMElement * aElement,
-                                          const nsAString & aAttribute,
+nsHTMLEditor::RemoveAttributeOrEquivalent(nsIDOMElement* aElement,
+                                          const nsAString& aAttribute,
                                           bool aSuppressTransaction)
 {
+  nsCOMPtr<dom::Element> element = do_QueryInterface(aElement);
+  NS_ENSURE_TRUE(element, NS_OK);
+
+  nsCOMPtr<nsIAtom> attribute = do_GetAtom(aAttribute);
+  MOZ_ASSERT(attribute);
+
   nsresult res = NS_OK;
   if (IsCSSEnabled() && mHTMLCSSUtils) {
-    res = mHTMLCSSUtils->RemoveCSSEquivalentToHTMLStyle(aElement, nullptr, &aAttribute, nullptr,
-                                                        aSuppressTransaction);
+    res = mHTMLCSSUtils->RemoveCSSEquivalentToHTMLStyle(
+        element, nullptr, &aAttribute, nullptr, aSuppressTransaction);
     NS_ENSURE_SUCCESS(res, res);
   }
 
-  nsAutoString existingValue;
-  bool wasSet = false;
-  res = GetAttributeValue(aElement, aAttribute, existingValue, &wasSet);
-  NS_ENSURE_SUCCESS(res, res);
-  if (wasSet) {
-    if (aSuppressTransaction)
-      res = aElement->RemoveAttribute(aAttribute);
-    else
+  if (element->HasAttr(kNameSpaceID_None, attribute)) {
+    if (aSuppressTransaction) {
+      res = element->UnsetAttr(kNameSpaceID_None, attribute,
+                               /* aNotify = */ true);
+    } else {
       res = RemoveAttribute(aElement, aAttribute);
+    }
   }
   return res;
 }