diff --git a/public/tier1/KeyValues.h b/public/tier1/KeyValues.h
index 7eb2f026..94ad15d7 100644
--- a/public/tier1/KeyValues.h
+++ b/public/tier1/KeyValues.h
@@ -25,6 +25,7 @@
 #include "utlvector.h"
 #include "Color.h"
 
+class IKeyValuesSystem;
 class IBaseFileSystem;
 class CUtlBuffer;
 class Color;
@@ -276,10 +277,15 @@ private:
 	char	   m_iDataType;
 	char	   m_bHasEscapeSequences; // true, if while parsing this KeyValue, Escape Sequences are used (default false)
 	char	   unused[2];
+	
+	IKeyValuesSystem* m_pKeyValuesSystem;
+	bool m_bHasCustomKeyvalueSystem;	
 
 	KeyValues *m_pPeer;	// pointer to next key in list
 	KeyValues *m_pSub;	// pointer to Start of a new sub key list
 	KeyValues *m_pChain;// Search here if it's not in our list
+	
+	void* m_pExpressionGetSymbolProc;
 };
 
 enum KeyValuesUnpackDestinationTypes_t
diff --git a/tier1/KeyValues.cpp b/tier1/KeyValues.cpp
index 7217799d..5415954f 100644
--- a/tier1/KeyValues.cpp
+++ b/tier1/KeyValues.cpp
@@ -301,6 +301,10 @@ void KeyValues::Init()
 
 	// for future proof
 	memset( unused, 0, sizeof(unused) );
+	
+	m_pKeyValuesSystem = NULL;
+	m_bHasCustomKeyvalueSystem = false;
+	m_pExpressionGetSymbolProc = NULL;
 }
 
 //-----------------------------------------------------------------------------