diff -Naur belle-sip-1.4.2-orig/src/belle_sip_headers_impl.c belle-sip-1.4.2-new/src/belle_sip_headers_impl.c
--- belle-sip-1.4.2-orig/src/belle_sip_headers_impl.c	2015-10-19 12:43:47.000000000 +0100
+++ belle-sip-1.4.2-new/src/belle_sip_headers_impl.c	2015-11-21 14:43:27.742412050 +0000
@@ -263,7 +263,11 @@
 }
 
 belle_sip_uri_t* belle_sip_header_address_get_uri(const belle_sip_header_address_t* address) {
-	return address->uri;
+	if (address) {
+		return address->uri;
+	} else {
+		return NULL;
+	}
 }
 
 void belle_sip_header_address_set_uri(belle_sip_header_address_t* address, belle_sip_uri_t* uri) {
diff -Naur belle-sip-1.4.2-orig/src/belle_sip_internal.h belle-sip-1.4.2-new/src/belle_sip_internal.h
--- belle-sip-1.4.2-orig/src/belle_sip_internal.h	2015-10-19 12:43:47.000000000 +0100
+++ belle-sip-1.4.2-new/src/belle_sip_internal.h	2015-11-21 14:40:31.276382513 +0000
@@ -291,7 +291,11 @@
 /*parameters accessors*/
 #define GET_SET_STRING(object_type,attribute) \
 	const char* object_type##_get_##attribute (const object_type##_t* obj) {\
-		return obj->attribute;\
+		if (obj) {\
+			return obj->attribute;\
+		} else {\
+			return NULL;\
+		}\
 	}\
 	void object_type##_set_##attribute (object_type##_t* obj,const char* value) {\
 		const char* previous_value = obj->attribute;  /*preserve if same value re-asigned*/ \
diff -Naur belle-sip-1.4.2-orig/src/belle_sip_object.c belle-sip-1.4.2-new/src/belle_sip_object.c
--- belle-sip-1.4.2-orig/src/belle_sip_object.c	2015-10-19 12:43:47.000000000 +0100
+++ belle-sip-1.4.2-new/src/belle_sip_object.c	2015-11-21 14:40:31.276382513 +0000
@@ -505,7 +505,10 @@
 }
 
 belle_sip_error_code belle_sip_object_marshal(belle_sip_object_t* obj, char* buff, size_t buff_size, size_t *offset) {
-	belle_sip_object_vptr_t *vptr=obj->vptr;
+	belle_sip_object_vptr_t *vptr = NULL;
+	if (obj != NULL) {
+		vptr=obj->vptr;
+	}
 	while (vptr != NULL) {
 		if (vptr->marshal != NULL) {
 			if (_belle_sip_object_marshal_check_enabled == TRUE)