diff --git a/json_object.c b/json_object.c
index e6bd870..b493b69 100644
--- a/json_object.c
+++ b/json_object.c
@@ -509,6 +509,8 @@ static int json_object_int_to_json_string(struct json_object* jso,
 					  int level,
 					  int flags)
 {
+	if (flags & JSON_C_TO_STRING_UINT64)
+		return sprintbuf(pb, "%"PRIu64, jso->o.c_int64);
 	return sprintbuf(pb, "%"PRId64, jso->o.c_int64);
 }
 
diff --git a/json_object.h b/json_object.h
index 5e0cf71..871b971 100644
--- a/json_object.h
+++ b/json_object.h
@@ -62,6 +62,11 @@ extern "C" {
  * A flag to drop trailing zero for float values
  */
 #define JSON_C_TO_STRING_NOZERO     (1<<2)
+/**
+ * Force integer to output unsigned
+ * Useful when dealing with very large 64 bit numbers without negatives
+ */
+#define JSON_C_TO_STRING_UINT64     (1<<4)
 
 #undef FALSE
 #define FALSE ((json_bool)0)