diff --git a/content/base/public/nsINode.h b/content/base/public/nsINode.h
index 2775c08a1c10..db6ea81d6aa5 100644
--- a/content/base/public/nsINode.h
+++ b/content/base/public/nsINode.h
@@ -60,8 +60,6 @@ namespace JS {
 class Value;
 }
 
-inline void SetDOMStringToNull(nsAString& aString);
-
 #define NODE_FLAG_BIT(n_) (1U << (n_))
 
 enum {
@@ -1494,10 +1492,7 @@ public:
   {
     SetNodeValueInternal(aNodeValue, aError);
   }
-  virtual void GetNodeValueInternal(nsAString& aNodeValue)
-  {
-    SetDOMStringToNull(aNodeValue);
-  }
+  virtual void GetNodeValueInternal(nsAString& aNodeValue);
   virtual void SetNodeValueInternal(const nsAString& aNodeValue,
                                     mozilla::ErrorResult& aError)
   {
@@ -1592,10 +1587,7 @@ protected:
     return IsEditableInternal();
   }
 
-  virtual void GetTextContentInternal(nsAString& aTextContent)
-  {
-    SetDOMStringToNull(aTextContent);
-  }
+  virtual void GetTextContentInternal(nsAString& aTextContent);
   virtual void SetTextContentInternal(const nsAString& aTextContent,
                                       mozilla::ErrorResult& aError)
   {
diff --git a/content/base/src/nsINode.cpp b/content/base/src/nsINode.cpp
index aa705159eb32..eb0f4899d854 100644
--- a/content/base/src/nsINode.cpp
+++ b/content/base/src/nsINode.cpp
@@ -324,6 +324,12 @@ nsINode::ChildNodes()
   return slots->mChildNodes;
 }
 
+void
+nsINode::GetTextContentInternal(nsAString& aTextContent)
+{
+  SetDOMStringToNull(aTextContent);
+}
+
 #ifdef DEBUG
 void
 nsINode::CheckNotNativeAnonymous() const
@@ -423,6 +429,12 @@ nsINode::GetOwnerDocument(nsIDOMDocument** aOwnerDocument)
   return ownerDoc ? CallQueryInterface(ownerDoc, aOwnerDocument) : NS_OK;
 }
 
+void
+nsINode::GetNodeValueInternal(nsAString& aNodeValue)
+{
+  SetDOMStringToNull(aNodeValue);
+}
+
 nsINode*
 nsINode::RemoveChild(nsINode& aOldChild, ErrorResult& aError)
 {