diff --git a/lib/struct.js b/lib/struct.js
index c72d24d..1108941 100644
--- a/lib/struct.js
+++ b/lib/struct.js
@@ -272,12 +272,13 @@ function recalc (struct) {
 
   function addType (type) {
     var offset = struct.size
-    var left = offset % struct.alignment
+    var align = type.indirection === 1 ? type.alignment : ref.alignof.pointer
+    var padding = (align - (offset % align)) % align
     var size = type.indirection === 1 ? type.size : ref.sizeof.pointer
 
-    if (size > left) {
-      offset += left
-    }
+    offset += padding
+
+    assert.equal(offset % align, 0, "offset should align")
 
     // adjust the "size" of the struct type
     struct.size = offset + size