diff --git a/arch/nt64/pthread_arch.h b/arch/nt64/pthread_arch.h
index 98babcd..fbbf3cd 100644
--- a/arch/nt64/pthread_arch.h
+++ b/arch/nt64/pthread_arch.h
@@ -1,7 +1,7 @@
 #include <stddef.h>
 
 #define	TP_ADJ(p)	(p)
-#define	CANCEL_REG_IP	16
+#define	CANCEL_REG_IP	0x1F
 
 extern uintptr_t __teb_sys_idx;
 extern uintptr_t __teb_libc_idx;