diff --git a/src/context.c b/src/context.c
index a861273d..50ee71c3 100644
--- a/src/context.c
+++ b/src/context.c
@@ -46,6 +46,8 @@
 #include "types-internal.h"
 #include "util-internal.h"
 
+void *plain_mem_funcs_user_arg = MF_PLAIN;
+
 /* Private functions */
 static uint16_t *create_default_namespaces(struct getdns_context *context);
 static struct getdns_list *create_default_root_servers();
@@ -72,7 +74,7 @@ static void cancel_dns_req(getdns_dns_req *);
 static uint16_t *
 create_default_namespaces(struct getdns_context *context)
 {
-	uint16_t *result = GETDNS_XMALLOC(context, uint16_t, 2);
+	uint16_t *result = GETDNS_XMALLOC(context->my_mf, uint16_t, 2);
 	result[0] = GETDNS_CONTEXT_NAMESPACE_LOCALNAMES;
 	result[1] = GETDNS_CONTEXT_NAMESPACE_DNS;
 	return result;
@@ -237,28 +239,40 @@ transaction_id_cmp(const void *id1, const void *id2)
  * Call this to initialize the context that is used in other getdns calls.
  */
 getdns_return_t
-getdns_context_create_with_memory_functions(struct getdns_context ** context,
+getdns_context_create_with_extended_memory_functions(
+    struct getdns_context ** context,
     int set_from_os,
-    void *(*malloc)(size_t),
-    void *(*realloc)(void *, size_t),
-    void (*free)(void *)
+    void *userarg,
+    void *(*malloc)(void *userarg, size_t),
+    void *(*realloc)(void *userarg, void *, size_t),
+    void (*free)(void *userarg, void *)
     )
 {
 	struct getdns_context *result = NULL;
+	mf_union mf;
 
 	if (!context || !malloc || !realloc || !free)
 		return GETDNS_RETURN_GENERIC_ERROR;
 
     /** default init **/
-	result = (*malloc)(sizeof(struct getdns_context));
+	mf.ext.malloc = malloc;
+	result = userarg == MF_PLAIN
+	       ? (*mf.pln.malloc)(         sizeof(struct getdns_context))
+	       : (*mf.ext.malloc)(userarg, sizeof(struct getdns_context));
 	if (!result) {
 		return GETDNS_RETURN_GENERIC_ERROR;
 	}
+	result->my_mf.mf_arg         = userarg;
+	result->my_mf.mf.ext.malloc  = malloc;
+	result->my_mf.mf.ext.realloc = realloc;
+	result->my_mf.mf.ext.free    = free;
 
 	result->update_callback = NULL;
-	result->malloc  = malloc;
-	result->realloc = realloc;
-	result->free    = free;
+
+	result->mf.mf_arg          = userarg;
+	result->mf.mf.ext.malloc   = malloc;
+	result->mf.mf.ext.realloc  = realloc;
+	result->mf.mf.ext.free     = free;
 
 	result->event_base_sync = event_base_new();
 	result->unbound_sync = ub_ctx_create_event(result->event_base_sync);
@@ -304,6 +318,28 @@ getdns_context_create_with_memory_functions(struct getdns_context ** context,
 	return GETDNS_RETURN_GOOD;
 }				/* getdns_context_create */
 
+/*
+ * getdns_context_create
+ *
+ * Call this to initialize the context that is used in other getdns calls.
+ */
+getdns_return_t
+getdns_context_create_with_memory_functions(struct getdns_context ** context,
+    int set_from_os,
+    void *(*malloc)(size_t),
+    void *(*realloc)(void *, size_t),
+    void (*free)(void *)
+    )
+{
+	mf_union mf;
+	mf.pln.malloc = malloc;
+	mf.pln.realloc = realloc;
+	mf.pln.free = free;
+	return getdns_context_create_with_extended_memory_functions(
+	    context, set_from_os, MF_PLAIN,
+	    mf.ext.malloc, mf.ext.realloc, mf.ext.free);
+}				/* getdns_context_create */
+
 /*
  * getdns_context_create
  *
@@ -330,7 +366,7 @@ getdns_context_destroy(struct getdns_context *context)
 		return;
 	}
 	if (context->namespaces)
-		GETDNS_FREE(context, context->namespaces);
+		GETDNS_FREE(context->my_mf, context->namespaces);
 
 	getdns_list_destroy(context->dns_root_servers);
 	getdns_list_destroy(context->suffix);
@@ -345,7 +381,7 @@ getdns_context_destroy(struct getdns_context *context)
 
 	ldns_rbtree_free(context->outbound_requests);
 
-	GETDNS_FREE(context, context);
+	GETDNS_FREE(context->my_mf, context);
 	return;
 }				/* getdns_context_destroy */
 
@@ -446,10 +482,10 @@ getdns_context_set_namespaces(struct getdns_context *context,
 	}
 
     /** clean up old namespaces **/
-	GETDNS_FREE(context, context->namespaces);
+	GETDNS_FREE(context->my_mf, context->namespaces);
 
     /** duplicate **/
-	context->namespaces = GETDNS_XMALLOC(context, uint16_t,
+	context->namespaces = GETDNS_XMALLOC(context->my_mf, uint16_t,
 	    namespace_count);
 	memcpy(context->namespaces, namespaces,
 	    namespace_count * sizeof(uint16_t));
@@ -783,6 +819,36 @@ getdns_context_set_edns_do_bit(struct getdns_context *context, uint8_t value)
 	return GETDNS_RETURN_GOOD;
 }				/* getdns_context_set_edns_do_bit */
 
+/*
+ * getdns_context_set_extended_memory_functions
+ *
+ */
+getdns_return_t
+getdns_context_set_extended_memory_functions(
+    struct getdns_context *context,
+    void *userarg,
+    void *(*malloc) (void *userarg, size_t),
+    void *(*realloc) (void *userarg, void *, size_t),
+    void (*free) (void *userarg, void *)
+    )
+{
+	if (!context)
+		return GETDNS_RETURN_BAD_CONTEXT;
+
+	if (!malloc || !realloc || !free)
+		return GETDNS_RETURN_CONTEXT_UPDATE_FAIL;
+
+	context->mf.mf_arg         = userarg;
+	context->mf.mf.ext.malloc  = malloc;
+	context->mf.mf.ext.realloc = realloc;
+	context->mf.mf.ext.free    = free;
+
+	dispatch_updated(context, GETDNS_CONTEXT_CODE_MEMORY_FUNCTIONS);
+
+	return GETDNS_RETURN_GOOD;
+} /* getdns_context_set_extended_memory_functions*/
+
+
 /*
  * getdns_context_set_memory_functions
  *
@@ -794,19 +860,12 @@ getdns_context_set_memory_functions(struct getdns_context *context,
     void (*free) (void *)
     )
 {
-	if (!context)
-		return GETDNS_RETURN_BAD_CONTEXT;
-
-	if (!malloc || !realloc || !free)
-		return GETDNS_RETURN_CONTEXT_UPDATE_FAIL;
-
-	context->malloc = malloc;
-	context->realloc = realloc;
-	context->free = free;
-
-	dispatch_updated(context, GETDNS_CONTEXT_CODE_MEMORY_FUNCTIONS);
-
-	return GETDNS_RETURN_GOOD;
+	mf_union mf;
+	mf.pln.malloc = malloc;
+	mf.pln.realloc = realloc;
+	mf.pln.free = free;
+	return getdns_context_set_extended_memory_functions(
+	    context, MF_PLAIN, mf.ext.malloc, mf.ext.realloc, mf.ext.free);
 } /* getdns_context_set_memory_functions*/
 
 
@@ -874,7 +933,7 @@ getdns_context_cancel_request(struct getdns_context *context,
 		user_pointer = req->user_pointer;
 
 		/* clean up */
-		GETDNS_FREE(context, node);
+		GETDNS_FREE(context->my_mf, node);
 		dns_req_free(req);
 
 		/* fire callback */
@@ -959,7 +1018,7 @@ getdns_context_track_outbound_request(getdns_dns_req * req)
 		return GETDNS_RETURN_GENERIC_ERROR;
 	}
 	struct getdns_context *context = req->context;
-	ldns_rbnode_t *node = GETDNS_MALLOC(context, ldns_rbnode_t);
+	ldns_rbnode_t *node = GETDNS_MALLOC(context->my_mf, ldns_rbnode_t);
 	if (!node) {
 		return GETDNS_RETURN_GENERIC_ERROR;
 	}
@@ -967,7 +1026,7 @@ getdns_context_track_outbound_request(getdns_dns_req * req)
 	node->data = req;
 	if (!ldns_rbtree_insert(context->outbound_requests, node)) {
 		/* free the node */
-		GETDNS_FREE(context, node);
+		GETDNS_FREE(context->my_mf, node);
 		return GETDNS_RETURN_GENERIC_ERROR;
 	}
 	return GETDNS_RETURN_GOOD;
@@ -983,16 +1042,16 @@ getdns_context_clear_outbound_request(getdns_dns_req * req)
 	ldns_rbnode_t *node = ldns_rbtree_delete(context->outbound_requests,
 	    &(req->trans_id));
 	if (node) {
-		GETDNS_FREE(context, node);
+		GETDNS_FREE(context->my_mf, node);
 	}
 	return GETDNS_RETURN_GOOD;
 }
 
 char *
-getdns_strdup(void *(*malloc)(size_t), const char *s)
+getdns_strdup(struct mem_funcs *mfs, const char *s)
 {
 	size_t sz = strlen(s) + 1;
-	char *r = (char *)(*malloc)(sizeof(char) * sz);
+	char *r = GETDNS_XMALLOC(*mfs, char, sz);
 	if (r)
 		return memcpy(r, s, sz);
 	else
@@ -1000,7 +1059,7 @@ getdns_strdup(void *(*malloc)(size_t), const char *s)
 }
 
 struct getdns_bindata *
-getdns_bindata_copy(void *(*malloc)(size_t), void (*free)(void *),
+getdns_bindata_copy(struct mem_funcs *mfs,
     const struct getdns_bindata *src)
 {
 	struct getdns_bindata *dst;
@@ -1008,14 +1067,14 @@ getdns_bindata_copy(void *(*malloc)(size_t), void (*free)(void *),
 	if (!src)
 		return NULL;
 	
-	dst = (struct getdns_bindata *)(*malloc)(sizeof(struct getdns_bindata));
+	dst = GETDNS_MALLOC(*mfs, struct getdns_bindata);
 	if (!dst)
 		return NULL;
 
 	dst->size = src->size;
-	dst->data = (uint8_t *)(*malloc)(sizeof(uint8_t) * src->size);
+	dst->data = GETDNS_XMALLOC(*mfs, uint8_t, src->size);
 	if (!dst->data) {
-		(*free)(dst);
+		GETDNS_FREE(*mfs, dst);
 		return NULL;
 	}
 	(void) memcpy(dst->data, src->data, src->size);
@@ -1023,11 +1082,12 @@ getdns_bindata_copy(void *(*malloc)(size_t), void (*free)(void *),
 }
 
 void
-getdns_bindata_destroy(void (*free)(void *), struct getdns_bindata *bindata)
+getdns_bindata_destroy(struct mem_funcs *mfs,
+    struct getdns_bindata *bindata)
 {
 	if (!bindata)
 		return;
-	(*free)(bindata->data);
-	(*free)(bindata);
+	GETDNS_FREE(*mfs, bindata->data);
+	GETDNS_FREE(*mfs, bindata);
 }
 /* getdns_context.c */
diff --git a/src/context.h b/src/context.h
index 2a04b147..803e90a3 100644
--- a/src/context.h
+++ b/src/context.h
@@ -31,6 +31,7 @@
 #define _GETDNS_CONTEXT_H_
 
 #include <getdns/getdns.h>
+#include "types-internal.h"
 
 struct event_base;
 struct getdns_dns_req;
@@ -58,9 +59,9 @@ struct getdns_context {
 	uint8_t edns_do_bit;
 
 	getdns_update_callback update_callback;
-	void *(*malloc)(size_t);
-	void *(*realloc)(void *, size_t);
-	void (*free)(void *);
+
+	struct mem_funcs mf;
+	struct mem_funcs my_mf;
 
 	/* Event loop for sync requests */
 	struct event_base *event_base_sync;
@@ -100,13 +101,14 @@ getdns_return_t getdns_context_clear_outbound_request(struct getdns_dns_req
 getdns_return_t getdns_context_cancel_request(struct getdns_context *context,
     getdns_transaction_t transaction_id, int fire_callback);
 
-char *getdns_strdup(void *(*malloc)(size_t), const char *str);
+char *getdns_strdup(struct mem_funcs *mfs, const char *str);
 
 struct getdns_bindata *getdns_bindata_copy(
-    void *(*malloc)(size_t), void (*free)(void *),
+    struct mem_funcs *mfs,
     const struct getdns_bindata *src);
 
-void getdns_bindata_destroy(void (*free)(void *),
+void getdns_bindata_destroy(
+    struct mem_funcs *mfs,
     struct getdns_bindata *bindata);
 
 #endif /* _GETDNS_CONTEXT_H_ */
diff --git a/src/dict.c b/src/dict.c
index 0592ec32..96523a73 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -63,8 +63,8 @@ getdns_dict_find(struct getdns_dict *dict, char *key, int addifnotfnd)
 
 	if (!item && addifnotfnd) {
 		/* tsearch will add a node automatically for us */
-		item = GETDNS_MALLOC(dict, struct getdns_dict_item);
-		item->node.key = getdns_strdup(dict->malloc, key);
+		item = GETDNS_MALLOC(dict->mf, struct getdns_dict_item);
+		item->node.key = getdns_strdup(&dict->mf, key);
 		item->data.n = 0;
 		ldns_rbtree_insert(&(dict->root), (ldns_rbnode_t *) item);
 	}
@@ -83,8 +83,9 @@ getdns_dict_get_names(struct getdns_dict * dict, struct getdns_list ** answer)
 	if (!dict || !answer)
 		return GETDNS_RETURN_NO_SUCH_DICT_NAME;
 
-	*answer = getdns_list_create_with_memory_functions(
-	    dict->malloc, dict->realloc, dict->free);
+	*answer = getdns_list_create_with_extended_memory_functions(
+	    dict->mf.mf_arg, dict->mf.mf.ext.malloc,
+	    dict->mf.mf.ext.realloc, dict->mf.mf.ext.free);
 	if (!*answer)
 		return GETDNS_RETURN_NO_SUCH_DICT_NAME;
 
@@ -188,34 +189,57 @@ getdns_dict_get_int(struct getdns_dict * dict, char *name, uint32_t * answer)
 }				/* getdns_dict_get_int */
 
 struct getdns_dict *
-getdns_dict_create_with_memory_functions(void *(*malloc)(size_t),
-    void *(*realloc)(void *, size_t), void (*free)(void *))
+getdns_dict_create_with_extended_memory_functions(
+    void *userarg,
+    void *(*malloc)(void *userarg, size_t),
+    void *(*realloc)(void *userarg, void *, size_t),
+    void (*free)(void *userarg, void *))
 {
 	struct getdns_dict *dict;
+	mf_union mf;
 
 	if (!malloc || !realloc || !free)
 		return NULL;
 
-	dict = (struct getdns_dict *)(*malloc)(sizeof(struct getdns_dict));
+	mf.ext.malloc = malloc;
+	dict = userarg == MF_PLAIN
+	     ? (struct getdns_dict*)(*mf.pln.malloc)(
+	           sizeof(struct getdns_dict))
+	     : (struct getdns_dict*)(*mf.ext.malloc)(userarg,
+	           sizeof(struct getdns_dict));
 	if (!dict)
 		return NULL;
 
-	dict->malloc  = malloc;
-	dict->realloc = realloc;
-	dict->free    = free;
+	dict->mf.mf_arg         = userarg;
+	dict->mf.mf.ext.malloc  = malloc;
+	dict->mf.mf.ext.realloc = realloc;
+	dict->mf.mf.ext.free    = free;
+
 	ldns_rbtree_init(&(dict->root),
 	    (int (*)(const void *, const void *)) strcmp);
 	return dict;
 }
 
+struct getdns_dict *
+getdns_dict_create_with_memory_functions(void *(*malloc)(size_t),
+    void *(*realloc)(void *, size_t), void (*free)(void *))
+{
+	mf_union mf;
+	mf.pln.malloc = malloc;
+	mf.pln.realloc = realloc;
+	mf.pln.free = free;
+	return getdns_dict_create_with_extended_memory_functions(
+	    MF_PLAIN, mf.ext.malloc, mf.ext.realloc, mf.ext.free);
+}
 
 /*-------------------------- getdns_dict_create_with_context */
 struct getdns_dict *
 getdns_dict_create_with_context(struct getdns_context *context)
 {
 	if (context)
-		return getdns_dict_create_with_memory_functions(context->malloc,
-		    context->realloc, context->free);
+		return getdns_dict_create_with_extended_memory_functions(
+		    context->mf.mf_arg, context->mf.mf.ext.malloc,
+		    context->mf.mf.ext.realloc, context->mf.mf.ext.free);
 	else
 		return getdns_dict_create_with_memory_functions(&malloc,
 		    &realloc, &free);
@@ -251,8 +275,11 @@ getdns_dict_copy(struct getdns_dict * srcdict, struct getdns_dict ** dstdict)
 		*dstdict = NULL;
 		return GETDNS_RETURN_GOOD;
 	}
-	*dstdict = getdns_dict_create_with_memory_functions(
-	    srcdict->malloc, srcdict->realloc, srcdict->free);
+	*dstdict = getdns_dict_create_with_extended_memory_functions(
+	    srcdict->mf.mf_arg,
+	    srcdict->mf.mf.ext.malloc,
+	    srcdict->mf.mf.ext.realloc,
+	    srcdict->mf.mf.ext.free);
 	if (!*dstdict)
 		return GETDNS_RETURN_NO_SUCH_DICT_NAME;
 
@@ -306,7 +333,7 @@ getdns_dict_item_free(ldns_rbnode_t * node, void *arg)
 
 	switch (item->dtype) {
 	case t_bindata:
-		getdns_bindata_destroy(dict->free, item->data.bindata);
+		getdns_bindata_destroy(&dict->mf, item->data.bindata);
 		break;
 	case t_dict:
 		getdns_dict_destroy(item->data.dict);
@@ -318,8 +345,8 @@ getdns_dict_item_free(ldns_rbnode_t * node, void *arg)
 		break;
 	}
 	if (item->node.key)
-		GETDNS_FREE(dict, (void *)item->node.key);
-	GETDNS_FREE(dict, item);
+		GETDNS_FREE(dict->mf, (void *)item->node.key);
+	GETDNS_FREE(dict->mf, item);
 }				/* getdns_dict_item_free */
 
 /*---------------------------------------- getdns_dict_destroy */
@@ -331,7 +358,7 @@ getdns_dict_destroy(struct getdns_dict *dict)
 
 	ldns_traverse_postorder(&(dict->root),
 	    getdns_dict_item_free, dict);
-	GETDNS_FREE(dict, dict);
+	GETDNS_FREE(dict->mf, dict);
 }				/* getdns_dict_destroy */
 
 /*---------------------------------------- getdns_dict_set_dict */
@@ -397,14 +424,13 @@ getdns_dict_set_bindata(struct getdns_dict * dict, char *name,
 	if (!dict || !name || !child_bindata)
 		return GETDNS_RETURN_NO_SUCH_DICT_NAME;
 
-	newbindata = getdns_bindata_copy(
-	    dict->malloc, dict->free, child_bindata);
+	newbindata = getdns_bindata_copy(&dict->mf, child_bindata);
 	if (!newbindata)
 		return GETDNS_RETURN_NO_SUCH_DICT_NAME;
 
 	item = getdns_dict_find(dict, name, 1);
 	if (!item) {
-		getdns_bindata_destroy(dict->free, newbindata);
+		getdns_bindata_destroy(&dict->mf, newbindata);
 		return GETDNS_RETURN_NO_SUCH_DICT_NAME;
 	}
 	item->dtype = t_bindata;
diff --git a/src/dict.h b/src/dict.h
index 26a72f96..caee054a 100644
--- a/src/dict.h
+++ b/src/dict.h
@@ -37,6 +37,7 @@
 
 #include <getdns/getdns.h>
 #include <ldns/rbtree.h>
+#include "types-internal.h"
 
 union getdns_item
 {
@@ -66,9 +67,7 @@ struct getdns_dict_item
 struct getdns_dict
 {
 	ldns_rbtree_t root;
-	void *(*malloc)(size_t);
-	void *(*realloc)(void *, size_t);
-	void (*free)(void *);
+	struct mem_funcs mf;
 };
 
 #endif
diff --git a/src/getdns/getdns.h b/src/getdns/getdns.h
index 121aadd8..0ef5c5f3 100644
--- a/src/getdns/getdns.h
+++ b/src/getdns/getdns.h
@@ -506,8 +506,16 @@ getdns_return_t getdns_dict_get_int(struct getdns_dict *this_dict, char *name,
 struct getdns_list *getdns_list_create();
 struct getdns_list *getdns_list_create_with_context(struct getdns_context *context);
 struct getdns_list *getdns_list_create_with_memory_functions(
-    void *(*malloc) (size_t), void *(*realloc) (void *, size_t),
-    void (*free) (void *));
+    void *(*malloc) (size_t),
+    void *(*realloc) (void *, size_t),
+    void (*free) (void *)
+);
+struct getdns_list *getdns_list_create_with_extended_memory_functions(
+    void *userarg,
+    void *(*malloc) (void *userarg, size_t),
+    void *(*realloc) (void *userarg, void *, size_t),
+    void (*free) (void *userarg, void *)
+);
 
 /**
  * free memory allocated to the list (also frees all children of the list)
@@ -567,8 +575,16 @@ getdns_return_t getdns_list_set_int(struct getdns_list *this_list, size_t index,
 struct getdns_dict *getdns_dict_create();
 struct getdns_dict *getdns_dict_create_with_context(struct getdns_context *context);
 struct getdns_dict *getdns_dict_create_with_memory_functions(
-    void *(*malloc) (size_t), void *(*realloc) (void *, size_t),
-    void (*free) (void *));
+    void *(*malloc) (size_t),
+    void *(*realloc) (void *, size_t),
+    void (*free) (void *)
+);
+struct getdns_dict *getdns_dict_create_with_extended_memory_functions(
+    void *userarg,
+    void *(*malloc) (void *userarg, size_t),
+    void *(*realloc) (void *userarg, void *, size_t),
+    void (*free) (void *userarg, void *)
+);
 
 /**
  * destroy a dictionary and all items within that dictionary
@@ -643,16 +659,27 @@ getdns_service(struct getdns_context *context,
     void *userarg,
     getdns_transaction_t * transaction_id, getdns_callback_t callbackfn);
 
-getdns_return_t getdns_context_create_with_memory_functions(
+getdns_return_t
+getdns_context_create(struct getdns_context ** context, int set_from_os);
+
+getdns_return_t
+getdns_context_create_with_memory_functions(
     struct getdns_context ** context,
     int set_from_os,
     void *(*malloc) (size_t),
     void *(*realloc) (void *, size_t),
     void (*free) (void *)
-    );
+);
 
-getdns_return_t getdns_context_create(struct getdns_context ** context,
-    int set_from_os);
+getdns_return_t
+getdns_context_create_with_extended_memory_functions(
+    struct getdns_context **context,
+    int set_from_os,
+    void *userarg,
+    void *(*malloc) (void *userarg, size_t),
+    void *(*realloc) (void *userarg, void *, size_t),
+    void (*free) (void *userarg, void *)
+);
 
 void getdns_context_destroy(struct getdns_context *context);
 
@@ -832,6 +859,14 @@ getdns_context_set_memory_functions(struct getdns_context *context,
     void (*free) (void *)
     );
 
+getdns_return_t
+getdns_context_set_extended_memory_functions(struct getdns_context *context,
+    void *userarg,
+    void *(*malloc) (void *userarg, size_t sz),
+    void *(*realloc) (void *userarg, void *ptr, size_t sz),
+    void (*free) (void *userarg, void *ptr)
+    );
+
 /* Extension - refactor to abstract async evt loop */
 /* For libevent, which we are using for these examples */
 getdns_return_t
diff --git a/src/list.c b/src/list.c
index c3890487..14a9d8cf 100644
--- a/src/list.c
+++ b/src/list.c
@@ -138,7 +138,7 @@ getdns_list_realloc(struct getdns_list *list)
 	if (!list)
 		return GETDNS_RETURN_GENERIC_ERROR;
 
-	newlist = GETDNS_XREALLOC(list, list->items,
+	newlist = GETDNS_XREALLOC(list->mf, list->items,
 	    struct getdns_list_item,
 	    list->numalloc + GETDNS_LIST_BLOCKSZ);
 	if (!newlist)
@@ -164,8 +164,12 @@ getdns_list_copy(struct getdns_list * srclist, struct getdns_list ** dstlist)
 		*dstlist = NULL;
 		return GETDNS_RETURN_GOOD;
 	}
-	*dstlist = getdns_list_create_with_memory_functions(
-	    srclist->malloc, srclist->realloc, srclist->free);
+	*dstlist = getdns_list_create_with_extended_memory_functions(
+	    srclist->mf.mf_arg,
+	    srclist->mf.mf.ext.malloc,
+	    srclist->mf.mf.ext.realloc,
+	    srclist->mf.mf.ext.free
+	);
 	if (!dstlist)
 		return GETDNS_RETURN_NO_SUCH_LIST_ITEM;
 
@@ -207,21 +211,32 @@ getdns_list_copy(struct getdns_list * srclist, struct getdns_list ** dstlist)
 }				/* getdns_list_copy */
 
 struct getdns_list *
-getdns_list_create_with_memory_functions(void *(*malloc)(size_t),
-    void *(*realloc)(void *, size_t), void (*free)(void *))
+getdns_list_create_with_extended_memory_functions(
+    void *userarg,
+    void *(*malloc)(void *userarg, size_t),
+    void *(*realloc)(void *userarg, void *, size_t),
+    void (*free)(void *userarg, void *))
 {
 	struct getdns_list *list;
+	mf_union mf;
 
 	if (!malloc || !realloc || !free)
 		return NULL;
 
-	list = (struct getdns_list *)(*malloc)(sizeof(struct getdns_list));
+	mf.ext.malloc = malloc;
+	list = userarg == MF_PLAIN
+	     ? (struct getdns_list *)(*mf.pln.malloc)(
+	           sizeof(struct getdns_list))
+	     : (struct getdns_list *)(*mf.ext.malloc)(userarg,
+	           sizeof(struct getdns_list));
 	if (!list)
 		return NULL;
 	
-	list->malloc   = malloc;
-	list->realloc  = realloc;
-	list->free     = free;
+	list->mf.mf_arg         = userarg;
+	list->mf.mf.ext.malloc  = malloc;
+	list->mf.mf.ext.realloc = realloc;
+	list->mf.mf.ext.free    = free;
+
 	list->numalloc = 0;
 	list->numinuse = 0;
 	list->items = NULL;
@@ -232,13 +247,30 @@ getdns_list_create_with_memory_functions(void *(*malloc)(size_t),
 	return list;
 }
 
+struct getdns_list *
+getdns_list_create_with_memory_functions(void *(*malloc)(size_t),
+    void *(*realloc)(void *, size_t), void (*free)(void *))
+{
+	mf_union mf;
+	mf.pln.malloc = malloc;
+	mf.pln.realloc = realloc;
+	mf.pln.free = free;
+	return getdns_list_create_with_extended_memory_functions(
+	    MF_PLAIN, mf.ext.malloc, mf.ext.realloc, mf.ext.free);
+}
+
+
 /*-------------------------- getdns_list_create_with_context */
 struct getdns_list *
 getdns_list_create_with_context(struct getdns_context *context)
 {
 	if (context)
-		return getdns_list_create_with_memory_functions(context->malloc,
-		    context->realloc, context->free);
+		return getdns_list_create_with_extended_memory_functions(
+		    context->mf.mf_arg,
+		    context->mf.mf.ext.malloc,
+		    context->mf.mf.ext.realloc,
+		    context->mf.mf.ext.free
+		);
 	else
 		return getdns_list_create_with_memory_functions(malloc,
 		    realloc, free);
@@ -271,7 +303,7 @@ getdns_list_destroy(struct getdns_list *list)
 			break;
 
 		case t_bindata:
-			getdns_bindata_destroy(list->free,
+			getdns_bindata_destroy(&list->mf,
 			    list->items[i].data.bindata);
 			break;
 
@@ -281,8 +313,8 @@ getdns_list_destroy(struct getdns_list *list)
 	}
 
 	if (list->items)
-		GETDNS_FREE(list, list->items);
-	GETDNS_FREE(list, list);
+		GETDNS_FREE(list->mf, list->items);
+	GETDNS_FREE(list->mf, list);
 }				/* getdns_list_destroy */
 
 /*---------------------------------------- getdns_list_add_item */
@@ -374,8 +406,7 @@ getdns_list_set_bindata(struct getdns_list * list, size_t index,
 	if (index >= list->numinuse)
 		return GETDNS_RETURN_NO_SUCH_LIST_ITEM;
 
-	newbindata = getdns_bindata_copy(
-	    list->malloc, list->free, child_bindata);
+	newbindata = getdns_bindata_copy(&list->mf, child_bindata);
 	if (!newbindata)
 		return GETDNS_RETURN_NO_SUCH_LIST_ITEM;
 
diff --git a/src/list.h b/src/list.h
index d5267769..b37266ae 100644
--- a/src/list.h
+++ b/src/list.h
@@ -31,6 +31,7 @@
 #define _GETDNS_LIST_H_
 
 #include <getdns/getdns.h>
+#include "types-internal.h"
 
 #define GETDNS_LIST_BLOCKSZ 10
 
@@ -63,10 +64,7 @@ struct getdns_list
 	int numalloc;
 	int numinuse;
 	struct getdns_list_item *items;
-	void *(*malloc)(size_t);
-	void *(*realloc)(void *, size_t);
-	void (*free)(void *);
+	struct mem_funcs mf;
 };
 
-
 #endif
diff --git a/src/request-internal.c b/src/request-internal.c
index 093a90db..7a11554a 100644
--- a/src/request-internal.c
+++ b/src/request-internal.c
@@ -44,10 +44,6 @@
 #include "util-internal.h"
 #include <unbound.h>
 
-/* useful macros */
-#define gd_malloc(sz) context->malloc(sz)
-#define gd_free(ptr) context->free(ptr)
-
 void
 network_req_free(getdns_network_req * net_req)
 {
@@ -58,7 +54,7 @@ network_req_free(getdns_network_req * net_req)
 	if (net_req->result) {
 		ldns_pkt_free(net_req->result);
 	}
-	gd_free(net_req);
+	GETDNS_FREE(context->mf, net_req);
 }
 
 getdns_network_req *
@@ -68,7 +64,8 @@ network_req_new(getdns_dns_req * owner,
 {
 
 	struct getdns_context *context = owner->context;
-	getdns_network_req *net_req = gd_malloc(sizeof(getdns_network_req));
+	getdns_network_req *net_req = GETDNS_MALLOC( context->mf
+	                                           , getdns_network_req);
 	if (!net_req) {
 		return NULL;
 	}
@@ -120,7 +117,7 @@ dns_req_free(getdns_dns_req * req)
 	/* free strduped name */
 	free(req->name);
 
-	gd_free(req);
+	GETDNS_FREE(context->mf, req);
 }
 
 /* create a new dns req to be submitted */
@@ -135,7 +132,7 @@ dns_req_new(struct getdns_context *context,
 	getdns_return_t r;
 	uint32_t both = GETDNS_EXTENSION_FALSE;
 
-	result = gd_malloc(sizeof(getdns_dns_req));
+	result = GETDNS_MALLOC(context->mf, getdns_dns_req);
 	if (result == NULL) {
 		return NULL;
 	}
diff --git a/src/types-internal.h b/src/types-internal.h
index 2859f6d2..ecb22a61 100644
--- a/src/types-internal.h
+++ b/src/types-internal.h
@@ -36,8 +36,9 @@
 #ifndef TYPES_INTERNAL_H_
 #define TYPES_INTERNAL_H_
 
-#include "context.h"
+#include <getdns/getdns.h>
 #include <ldns/ldns.h>
+struct getdns_context;
 
 /**
  * \defgroup strings String Constants
@@ -175,16 +176,45 @@ typedef struct getdns_dns_req
 
 } getdns_dns_req;
 
+#define MF_PLAIN ((void *)&plain_mem_funcs_user_arg)
+extern void *plain_mem_funcs_user_arg;
+
+typedef union {
+		struct {
+			void *(*malloc)(size_t);
+			void *(*realloc)(void *, size_t);
+			void (*free)(void *);
+		} pln;
+		struct {
+			void *(*malloc)(void *userarg, size_t);
+			void *(*realloc)(void *userarg, void *, size_t);
+			void (*free)(void *userarg, void *);
+		} ext;
+	} mf_union;
+
+struct mem_funcs {
+	void *mf_arg;
+	mf_union mf;
+};
+
 #define GETDNS_XMALLOC(obj, type, count)	\
-    ((obj) ? ((type *) (*(obj)->malloc)((count)*sizeof(type))) \
-           : ((type *)          malloc ((count)*sizeof(type))))
+    ((obj).mf_arg == MF_PLAIN \
+    ? ((type *)(*(obj).mf.pln.malloc)(              (count)*sizeof(type))) \
+    : ((type *)(*(obj).mf.ext.malloc)((obj).mf_arg, (count)*sizeof(type))) \
+    )
 
 #define GETDNS_XREALLOC(obj, ptr, type, count)	\
-    ((obj) ? ((type *) (*(obj)->realloc)((ptr),(count)*sizeof(type))) \
-           : ((type *)          realloc ((ptr),(count)*sizeof(type))))
+    ((obj).mf_arg == MF_PLAIN \
+    ? ((type *)(*(obj).mf.pln.realloc)( (ptr), (count)*sizeof(type))) \
+    : ((type *)(*(obj).mf.ext.realloc)( (obj).mf_arg                  \
+                                      , (ptr), (count)*sizeof(type))) \
+    )
 
-#define GETDNS_FREE(obj, ptr)			\
-    ((obj) ? ((*(obj)->free)(ptr)) : free(ptr))
+#define GETDNS_FREE(obj, ptr)	\
+    ((obj).mf_arg == MF_PLAIN \
+    ? ((*(obj).mf.pln.free)(              (ptr))) \
+    : ((*(obj).mf.ext.free)((obj).mf_arg, (ptr))) \
+    )
 
 #define GETDNS_MALLOC(obj, type)	GETDNS_XMALLOC(obj, type, 1)
 #define GETDNS_REALLOC(obj, ptr, type)	GETDNS_XREALLOC(obj, ptr, type, 1);