diff --git a/accessible/xpcom/xpcAccessible.cpp b/accessible/xpcom/xpcAccessible.cpp
index 66abcc7cfd6..76e01bf4acf 100644
--- a/accessible/xpcom/xpcAccessible.cpp
+++ b/accessible/xpcom/xpcAccessible.cpp
@@ -23,6 +23,7 @@ NS_IMETHODIMP
 xpcAccessible::GetParent(nsIAccessible** aParent)
 {
   NS_ENSURE_ARG_POINTER(aParent);
+  *aParent = nullptr;
   if (!Intl())
     return NS_ERROR_FAILURE;
 
@@ -146,6 +147,10 @@ NS_IMETHODIMP
 xpcAccessible::GetIndexInParent(int32_t* aIndexInParent)
 {
   NS_ENSURE_ARG_POINTER(aIndexInParent);
+  *aIndexInParent = -1;
+
+  if (!Intl())
+    return NS_ERROR_FAILURE;
 
   *aIndexInParent = Intl()->IndexInParent();
   return *aIndexInParent != -1 ? NS_OK : NS_ERROR_FAILURE;
@@ -157,6 +162,9 @@ xpcAccessible::GetDOMNode(nsIDOMNode** aDOMNode)
   NS_ENSURE_ARG_POINTER(aDOMNode);
   *aDOMNode = nullptr;
 
+  if (!Intl())
+    return NS_ERROR_FAILURE;
+
   nsINode* node = Intl()->GetNode();
   if (node)
     CallQueryInterface(node, aDOMNode);
@@ -168,6 +176,10 @@ NS_IMETHODIMP
 xpcAccessible::GetDocument(nsIAccessibleDocument** aDocument)
 {
   NS_ENSURE_ARG_POINTER(aDocument);
+  *aDocument = nullptr;
+
+  if (!Intl())
+    return NS_ERROR_FAILURE;
 
   NS_IF_ADDREF(*aDocument = ToXPCDocument(Intl()->Document()));
   return NS_OK;
@@ -177,6 +189,10 @@ NS_IMETHODIMP
 xpcAccessible::GetRootDocument(nsIAccessibleDocument** aRootDocument)
 {
   NS_ENSURE_ARG_POINTER(aRootDocument);
+  *aRootDocument = nullptr;
+
+  if (!Intl())
+    return NS_ERROR_FAILURE;
 
   NS_IF_ADDREF(*aRootDocument = ToXPCDocument(Intl()->RootAccessible()));
   return NS_OK;
@@ -199,7 +215,7 @@ NS_IMETHODIMP
 xpcAccessible::GetState(uint32_t* aState, uint32_t* aExtraState)
 {
   NS_ENSURE_ARG_POINTER(aState);
-  
+
   if (!Intl())
     nsAccUtils::To32States(states::DEFUNCT, aState, aExtraState);
   else