diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 7fc98f4..14fd26b 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -19,6 +19,7 @@
 
 /* ld/ldx fields */
 #define BPF_DW		0x18	/* double word (64-bit) */
+#define BPF_MEMSX	0x80	/* load with sign extension */
 #define BPF_ATOMIC	0xc0	/* atomic memory ops - op type in immediate */
 #define BPF_XADD	0xc0	/* exclusive add - legacy name */