diff --git a/zecsy.hpp b/zecsy.hpp
index 117aef0..e7f40bf 100644
--- a/zecsy.hpp
+++ b/zecsy.hpp
@@ -97,7 +97,6 @@ namespace zecsy
             std::vector<uint8_t> data;
             std::vector<size_t> free_list;
             std::unordered_map<entity_id, size_t> entity_to_index;
-            std::unordered_map<size_t, entity_id> index_to_entity;
         };
 
         std::unordered_map<comp_id, component_pool> pools;
@@ -198,7 +197,6 @@ namespace zecsy
                 auto& pool = pools[id];
                 auto index = pool.entity_to_index[e];
                 pool.entity_to_index.erase(e);
-                pool.index_to_entity.erase(index);
                 pool.free_list.emplace_back(index);
             }
         }
@@ -256,7 +254,6 @@ namespace zecsy
 
         new(&pool.data[index * sizeof(T)]) T(comp);
         pool.entity_to_index[e] = index;
-        pool.index_to_entity[index] = e;
 
         auto& archetype = entity_to_comps[e];
         auto old_archetype = archetype;
@@ -305,7 +302,6 @@ namespace zecsy
         auto index = pool.entity_to_index[e];
         pool.free_list.push_back(index);
         pool.entity_to_index.erase(e);
-        pool.index_to_entity.erase(index);
     }
 
     template<Component First, Component Second, Component... Rest>