diff --git a/src/arena.c b/src/arena.c
index 58466cc..e78f74b 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -13,8 +13,8 @@ arena_initialize(u64 size, b8 growable)
     result->current = result;
 
     // rhjr: immutable arena header
-    result->base_pos = sizeof(Arena);
-    result->offset = sizeof(Arena);
+    result->base_pos = memory_align_power_of_two(sizeof(Arena));
+    result->offset = memory_align_power_of_two(sizeof(Arena));
 
     result->growable = growable;
     result->size = size;