diff --git a/xen/common/unlzma.c b/xen/common/unlzma.c
index 103d2df596..a7da55b023 100644
--- a/xen/common/unlzma.c
+++ b/xen/common/unlzma.c
@@ -214,11 +214,11 @@ rc_bit_tree_decode(struct rc *rc, uint16_t *p, int num_levels, int *symbol)
  */
 
 
-struct __packed lzma_header {
+struct lzma_header {
 	uint8_t pos;
 	uint32_t dict_size;
 	uint64_t dst_size;
-};
+} __attribute__((packed)) ;
 
 
 #define LZMA_BASE_SIZE 1846