diff --git a/include/ntapi/bits/nt64/nt_thread_x86_64.h b/include/ntapi/bits/nt64/nt_thread_x86_64.h
index d8909ba..6c6a877 100644
--- a/include/ntapi/bits/nt64/nt_thread_x86_64.h
+++ b/include/ntapi/bits/nt64/nt_thread_x86_64.h
@@ -97,6 +97,7 @@ typedef struct {
 	uintptr_t		uc_last_branch_from_rip;	/* 0x4b8 */
 	uintptr_t		uc_last_exception_to_rip;	/* 0x4c0 */
 	uintptr_t		uc_last_exception_from_rip;	/* 0x4c8 */
+	uintptr_t		uc_reserved[6];			/* 0x4d0 */
 } nt_mcontext_x86_64_t;
 
 #endif