diff --git a/hipadaba.c b/hipadaba.c
index 594e638c..9477eb67 100644
--- a/hipadaba.c
+++ b/hipadaba.c
@@ -158,12 +158,12 @@ static pHdbCallback DeleteForID(pHdbCallback root, int id){
     return result;
 }
 /*-----------------------------------------------------------------------*/
-static pHdbCallback DeleteForInternalID(pHdbCallback root, int id){
+static pHdbCallback DeleteForInternalID(pHdbCallback root, void *id){
     pHdbCallback current = root;
     pHdbCallback tmp = NULL;
     pHdbCallback result = NULL;
 
-    if(root == NULL){
+    if(root == NULL || id == NULL){
         return NULL;
     }
     
@@ -729,7 +729,7 @@ char *GetHipadabaPath(pHdb node){
 /*==================== Callback Functions ==================================*/
 pHdbCallback MakeHipadabaCallback(hdbCallbackFunction func, 
                        void *userData, killUserData killFunc,
-                       int id, int internalID){
+                       int id, void *internalID){
     pHdbCallback pNew = NULL;
     
     assert(func != NULL);
@@ -751,6 +751,7 @@ pHdbCallback MakeHipadabaCallback(hdbCallbackFunction func,
 void AppendHipadabaCallback(pHdb node, int type, pHdbCallback newCB){
     pHdbCallback current = NULL;
     
+    assert(node);
     switch(type){
         case HCBSET:
             if(node->writeCallbacks == NULL){
@@ -860,7 +861,7 @@ void RemoveHipadabaCallback(pHdb root, int id){
     }
 }
 /*----------------------------------------------------------------------------*/
-void InternalRemoveHipadabaCallback(pHdb root, int internalID){
+void InternalRemoveHipadabaCallback(pHdb root, void *internalID){
     pHdb current = NULL;
     
     root->writeCallbacks = DeleteForInternalID(root->writeCallbacks,internalID);
diff --git a/hipadaba.h b/hipadaba.h
index fdc90d56..6ff1b7f0 100644
--- a/hipadaba.h
+++ b/hipadaba.h
@@ -87,7 +87,7 @@ typedef struct __hdbcallback {
         killUserData killFunc;
         hdbCallbackFunction userCallback;
         int id;
-        int internalID;
+        void *internalID;
         struct __hdbcallback *next;
         struct __hdbcallback *previous;
         }hdbCallback, *pHdbCallback;
@@ -250,14 +250,14 @@ int CountHdbChildren(pHdb node);
  * @param killFunc A function for freeing the userData. Can be NULL, then it will 
  * not be invoked
  * @param id An ID associated with this callback
- * @param internalID Another ID to be associated with this callback. ID's come in
- * useful when callbacks have to be deleted in  a later stage.
- * @return A new suitabvly initialised callback structure or NULL when required elements 
+ * @param internalID Another ID to be associated with this callback. Typically a
+ * reference to the owner object responsible for deleting the callback.
+ * @return A new suitabaly initialised callback structure or NULL when required elements 
  * are missing or there is nor memory.
  */   
 pHdbCallback MakeHipadabaCallback(hdbCallbackFunction func, 
 				       void *userData, killUserData killFunc,
-				       int id, int internalID);
+				       int id, void *internalID);
 /**
  * add a callback at the end of the callback chain
  * @param node The node to which to append the callback
@@ -283,7 +283,7 @@ void RemoveHipadabaCallback(pHdb root, int id);
  * @param root The starting node from where to start removing callbacks
  * @param internalID The internal ID callbacks have to match in order to be removed.
  */
-void InternalRemoveHipadabaCallback(pHdb root, int internalID);
+void InternalRemoveHipadabaCallback(pHdb root, void *internalID);
 /**
  * invoke a callback chain.
  * @param root The callback chain to invoke