diff --git a/public/icvar.h b/public/icvar.h
index b30c15a8..6558277d 100644
--- a/public/icvar.h
+++ b/public/icvar.h
@@ -79,8 +79,8 @@ public:
 	virtual void SetMaxSplitScreenSlots(int nSlots) = 0;
 	virtual int	GetMaxSplitScreenSlots() const = 0;
 
-	virtual void RegisterCreationListeners(CCreationListenerCallbacks *callbacks) = 0;
-	virtual void RemoveCreationListeners(CCreationListenerCallbacks *callbacks) = 0;
+	virtual void RegisterCreationListeners(ICreationListenerCallbacks *callbacks) = 0;
+	virtual void RemoveCreationListeners(ICreationListenerCallbacks *callbacks) = 0;
 
 	virtual void unk1() = 0;
 
diff --git a/public/tier1/convar.h b/public/tier1/convar.h
index 8ee50b6e..cfb8a5f1 100644
--- a/public/tier1/convar.h
+++ b/public/tier1/convar.h
@@ -118,21 +118,13 @@ typedef void(*FnChangeCallback_t)(ConVarRefAbstract *cvar, CSplitScreenSlot nSlo
 //-----------------------------------------------------------------------------
 // ConVar & ConCommand creation listener callbacks
 //-----------------------------------------------------------------------------
-struct CCreationListenerCallbacks
+class ICreationListenerCallbacks
 {
-	void(*FnConVarCreationCallback)(CCreationListenerCallbacks *pThisCallback, ConVarRefAbstract *pNewCvar);
-	void(*FnConCommandCreationCallback)(CCreationListenerCallbacks *pThisCallback, ConCommandID commandID);
+public:
+	virtual void ConVarCreationCallback(ConVarRefAbstract *pNewCvar) = 0;
+	virtual void ConCommandCreationCallback(ConCommandID commandID) = 0;
 };
 
-//-----------------------------------------------------------------------------
-// Forward declarations
-//-----------------------------------------------------------------------------
-class ConVar;
-class CCommand;
-class ConCommand;
-class ConCommandBase;
-struct characterset_t;
-
 struct CCommandContext
 {
 	CCommandContext( int index )