diff --git a/spa/include/spa/support/system.h b/spa/include/spa/support/system.h
index 3d287da04..56ceea648 100644
--- a/spa/include/spa/support/system.h
+++ b/spa/include/spa/support/system.h
@@ -59,8 +59,15 @@ struct spa_system { struct spa_interface iface; };
 
 struct spa_poll_event {
 	uint32_t events;
-	void *data;
-} __attribute__ ((packed));
+	union {
+		void *data;
+		uint64_t data_u64;
+	};
+#ifdef __x86_64__
+} __attribute__((packed));
+#else
+};
+#endif
 
 struct spa_system_methods {
 #define SPA_VERSION_SYSTEM_METHODS	1
diff --git a/spa/plugins/support/system.c b/spa/plugins/support/system.c
index d48636e2e..cd9e1c6eb 100644
--- a/spa/plugins/support/system.c
+++ b/spa/plugins/support/system.c
@@ -31,6 +31,8 @@ SPA_LOG_TOPIC_DEFINE_STATIC(log_topic, "spa.system");
 #endif
 
 SPA_STATIC_ASSERT(sizeof(struct spa_poll_event) == sizeof(struct epoll_event));
+SPA_STATIC_ASSERT(offsetof(struct spa_poll_event, events) == offsetof(struct epoll_event, events));
+SPA_STATIC_ASSERT(offsetof(struct spa_poll_event, data) == offsetof(struct epoll_event, data.ptr));
 
 struct impl {
 	struct spa_handle handle;