diff --git a/src/basic/missing.h b/src/basic/missing.h
index 3e2c0afc85..20a1c5f1b9 100644
--- a/src/basic/missing.h
+++ b/src/basic/missing.h
@@ -589,6 +589,10 @@ struct btrfs_ioctl_quota_ctl_args {
 #define EFIVARFS_MAGIC 0xde5e81e4
 #endif
 
+#ifndef SMACK_MAGIC
+#define SMACK_MAGIC 0x43415d53
+#endif
+
 #ifndef MAX_HANDLE_SZ
 #define MAX_HANDLE_SZ 128
 #endif