diff --git a/src/ikarus/id.cpp b/src/ikarus/id.cpp
index 031c490..4269215 100644
--- a/src/ikarus/id.cpp
+++ b/src/ikarus/id.cpp
@@ -3,7 +3,7 @@
 #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) - IKARUS_ID_OBJECT_TYPE_BITS;
+constexpr 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 {
     return data | (static_cast<IkarusId>(type) << IKARUS_ID_OBJECT_RANDOM_BITS);