diff --git a/Include/Fledasty/Core/HashTable.h b/Include/Fledasty/Core/HashTable.h
index 7e23655..29f9dbf 100644
--- a/Include/Fledasty/Core/HashTable.h
+++ b/Include/Fledasty/Core/HashTable.h
@@ -119,12 +119,21 @@ FledastyError fledasty_hash_table_##name##_insert(FledastyHashTable_##name *curr
         hallocy_free(previous_table);                                                                                                                                                   \
     }                                                                                                                                                                                   \
                                                                                                                                                                                         \
-    const size_t index = current_hash_table->hash_function(key) % current_hash_table->capacity;                                                                                         \
-                                                                                                                                                                                        \
     FledastyHashTablePair_##name pair = { .key = key, .value = value };                                                                                                                 \
-    fledasty_dynamic_array_fledasty_internal_pair_append(&current_hash_table->Table[index], pair);                                                                                      \
+    const size_t index = current_hash_table->hash_function(key) % current_hash_table->capacity;                                                                                         \
+    if (fledasty_dynamic_array_fledasty_internal_pair_has_value(&current_hash_table->Table[index], pair)) {                                                                             \
+        size_t key_index = 0;                                                                                                                                                           \
+        while (!compare_key_function(current_hash_table->Table[index].buffer[key_index].key, key)) {                                                                                    \
+            key_index += 1;                                                                                                                                                             \
+        }                                                                                                                                                                               \
                                                                                                                                                                                         \
+        current_hash_table->Table[index].buffer[key_index].value = value;                                                                                                               \
+        return FLEDASTY_ERROR_VALUE_REPLACED;                                                                                                                                           \
+    }                                                                                                                                                                                   \
+                                                                                                                                                                                        \
+    fledasty_dynamic_array_fledasty_internal_pair_append(&current_hash_table->Table[index], pair);                                                                                      \
     current_hash_table->size += 1;                                                                                                                                                      \
+                                                                                                                                                                                        \
     return FLEDASTY_ERROR_NONE;                                                                                                                                                         \
 }                                                                                                                                                                                       \
                                                                                                                                                                                         \