diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 3ed759f53e7c..fd2309512978 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -647,8 +647,21 @@ int btf__align_of(const struct btf *btf, __u32 id)
 			if (align <= 0)
 				return libbpf_err(align);
 			max_align = max(max_align, align);
+
+			/* if field offset isn't aligned according to field
+			 * type's alignment, then struct must be packed
+			 */
+			if (btf_member_bitfield_size(t, i) == 0 &&
+			    (m->offset % (8 * align)) != 0)
+				return 1;
 		}
 
+		/* if struct/union size isn't a multiple of its alignment,
+		 * then struct must be packed
+		 */
+		if ((t->size % max_align) != 0)
+			return 1;
+
 		return max_align;
 	}
 	default: