diff --git a/kitty/systemd.c b/kitty/systemd.c
index 65d9e2fb6..9d19559ac 100644
--- a/kitty/systemd.c
+++ b/kitty/systemd.c
@@ -32,6 +32,7 @@ typedef struct {
     const char *name;
     const char *message;
     int _need_free;
+    int64_t filler;  // just in case systemd ever increases the size of this struct
 } sd_bus_error;
 typedef struct sd_bus_message sd_bus_message;