diff --git a/src/ikarus/id.cpp b/src/ikarus/id.cpp
index 4269215..9749667 100644
--- a/src/ikarus/id.cpp
+++ b/src/ikarus/id.cpp
@@ -2,13 +2,13 @@
 
 #include <ikarus/objects/object_type.h>
 
-constexpr uint64_t IKARUS_ID_OBJECT_TYPE_BITS = 8;
-constexpr uint64_t IKARUS_ID_OBJECT_RANDOM_BITS = sizeof(IkarusId) * 8 - IKARUS_ID_OBJECT_TYPE_BITS;
+uint64_t IKARUS_ID_OBJECT_TYPE_BITS = 8;
+uint64_t IKARUS_ID_OBJECT_RANDOM_BITS = sizeof(IkarusId) * 8 - IKARUS_ID_OBJECT_TYPE_BITS;
 
-auto ikarus_id_from_data_and_type(int64_t data, IkarusObjectType type) -> IkarusId {
+IkarusId ikarus_id_from_data_and_type(int64_t data, IkarusObjectType type) {
     return data | (static_cast<IkarusId>(type) << IKARUS_ID_OBJECT_RANDOM_BITS);
 }
 
-auto ikarus_id_get_object_type(IkarusId id) -> IkarusObjectType {
+IkarusObjectType ikarus_id_get_object_type(IkarusId id) {
     return static_cast<IkarusObjectType>(id >> IKARUS_ID_OBJECT_RANDOM_BITS);
 }