diff --git a/dom/html/HTMLTableElement.cpp b/dom/html/HTMLTableElement.cpp
index aa7cae6c2bf7..a0913e6b4620 100644
--- a/dom/html/HTMLTableElement.cpp
+++ b/dom/html/HTMLTableElement.cpp
@@ -589,11 +589,10 @@ already_AddRefed<nsGenericHTMLElement> HTMLTableElement::CreateTHead() {
 }
 
 void HTMLTableElement::DeleteTHead() {
-  HTMLTableSectionElement* tHead = GetTHead();
+  RefPtr<HTMLTableSectionElement> tHead = GetTHead();
   if (tHead) {
-    mozilla::ErrorResult rv;
+    mozilla::IgnoredErrorResult rv;
     nsINode::RemoveChild(*tHead, rv);
-    MOZ_ASSERT(!rv.Failed());
   }
 }
 
@@ -616,11 +615,10 @@ already_AddRefed<nsGenericHTMLElement> HTMLTableElement::CreateTFoot() {
 }
 
 void HTMLTableElement::DeleteTFoot() {
-  HTMLTableSectionElement* tFoot = GetTFoot();
+  RefPtr<HTMLTableSectionElement> tFoot = GetTFoot();
   if (tFoot) {
-    mozilla::ErrorResult rv;
+    mozilla::IgnoredErrorResult rv;
     nsINode::RemoveChild(*tFoot, rv);
-    MOZ_ASSERT(!rv.Failed());
   }
 }
 
@@ -644,11 +642,10 @@ already_AddRefed<nsGenericHTMLElement> HTMLTableElement::CreateCaption() {
 }
 
 void HTMLTableElement::DeleteCaption() {
-  HTMLTableCaptionElement* caption = GetCaption();
+  RefPtr<HTMLTableCaptionElement> caption = GetCaption();
   if (caption) {
-    mozilla::ErrorResult rv;
+    mozilla::IgnoredErrorResult rv;
     nsINode::RemoveChild(*caption, rv);
-    MOZ_ASSERT(!rv.Failed());
   }
 }
 
diff --git a/dom/html/HTMLTableSectionElement.cpp b/dom/html/HTMLTableSectionElement.cpp
index 1e10952556cc..4ac5b4c37a24 100644
--- a/dom/html/HTMLTableSectionElement.cpp
+++ b/dom/html/HTMLTableSectionElement.cpp
@@ -105,7 +105,7 @@ void HTMLTableSectionElement::DeleteRow(int32_t aValue, ErrorResult& aError) {
     refIndex = (uint32_t)aValue;
   }
 
-  nsINode* row = rows->Item(refIndex);
+  nsCOMPtr<nsINode> row = rows->Item(refIndex);
   if (!row) {
     aError.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
     return;