diff --git a/ebtree/ebtree.h b/ebtree/ebtree.h
index 2e6ba03..0ba42f1 100644
--- a/ebtree/ebtree.h
+++ b/ebtree/ebtree.h
@@ -370,6 +370,8 @@
  * and one for the node, which remains unused in the very first node inserted
  * into the tree. This structure is 20 bytes per node on 32-bit machines. Do
  * not change the order, benchmarks have shown that it's optimal this way.
+ * Note: be careful about this struct's alignment if it gets included into
+ * another struct and some atomic ops are expected on the keys or the node.
  */
 struct eb_node {
 	struct eb_root branches; /* branches, must be at the beginning */
@@ -377,7 +379,10 @@
 	eb_troot_t    *leaf_p;  /* leaf node's parent */
 	short int      bit;     /* link's bit position. */
 	short unsigned int pfx; /* data prefix length, always related to leaf */
-} __attribute__((packed));
+}
+#ifdef HA_UNALIGNED
+   __attribute__((packed));
+#endif
 
 /* Return the structure of type <type> whose member <member> points to <ptr> */
 #define eb_entry(ptr, type, member) container_of(ptr, type, member)