diff --git a/sys/sys/rangelock.h b/sys/sys/rangelock.h
index 32ccf3427b4..ea3d0c26cd3 100644
--- a/sys/sys/rangelock.h
+++ b/sys/sys/rangelock.h
@@ -50,6 +50,12 @@ struct rl_q_entry;
 struct rangelock {
 	uintptr_t head;
 	bool sleepers;
+	uint8_t resv1;
+	uint8_t resv2;
+	uint8_t resv3;
+#if __SIZEOF_LONG__ >= 8
+	uint32_t resv4;
+#endif
 };
 
 #ifdef _KERNEL