diff --git a/tinyxml2.cpp b/tinyxml2.cpp
index 6e68caf..90536a2 100755
--- a/tinyxml2.cpp
+++ b/tinyxml2.cpp
@@ -672,11 +672,7 @@ XMLNode* XMLNode::InsertEndChild( XMLNode* addThis )
         TIXMLASSERT( false );
         return 0;
     }
-
-	if (addThis->_parent)
-		addThis->_parent->Unlink( addThis );
-	else
-	   addThis->_memPool->SetTracked();
+    BeforeInsertChild( addThis );
 
     if ( _lastChild ) {
         TIXMLASSERT( _firstChild );
@@ -706,11 +702,7 @@ XMLNode* XMLNode::InsertFirstChild( XMLNode* addThis )
         TIXMLASSERT( false );
         return 0;
     }
-
-	if (addThis->_parent)
-		addThis->_parent->Unlink( addThis );
-	else
-	   addThis->_memPool->SetTracked();
+    BeforeInsertChild( addThis );
 
     if ( _firstChild ) {
         TIXMLASSERT( _lastChild );
@@ -753,10 +745,7 @@ XMLNode* XMLNode::InsertAfterChild( XMLNode* afterThis, XMLNode* addThis )
         // The last node or the only node.
         return InsertEndChild( addThis );
     }
-	if (addThis->_parent)
-		addThis->_parent->Unlink( addThis );
-	else
-	   addThis->_memPool->SetTracked();
+    BeforeInsertChild( addThis );
     addThis->_prev = afterThis;
     addThis->_next = afterThis->_next;
     afterThis->_next->_prev = addThis;
@@ -906,6 +895,17 @@ void XMLNode::DeleteNode( XMLNode* node )
     pool->Free( node );
 }
 
+void XMLNode::BeforeInsertChild( XMLNode* insertThis ) const
+{
+    TIXMLASSERT( insertThis );
+    TIXMLASSERT( insertThis->_document == _document );
+
+    if ( insertThis->_parent )
+        insertThis->_parent->Unlink( insertThis );
+    else
+        insertThis->_memPool->SetTracked();
+}
+
 // --------- XMLText ---------- //
 char* XMLText::ParseDeep( char* p, StrPair* )
 {
diff --git a/tinyxml2.h b/tinyxml2.h
index 279b778..257e8fd 100755
--- a/tinyxml2.h
+++ b/tinyxml2.h
@@ -894,6 +894,7 @@ private:
     MemPool*		_memPool;
     void Unlink( XMLNode* child );
     static void DeleteNode( XMLNode* node );
+    void BeforeInsertChild( XMLNode* insertThis ) const;
 };