diff --git a/src/hardware/fx2lafw/protocol.h b/src/hardware/fx2lafw/protocol.h
index f1a93f99..50e0ea4b 100644
--- a/src/hardware/fx2lafw/protocol.h
+++ b/src/hardware/fx2lafw/protocol.h
@@ -62,9 +62,11 @@
 #define CMD_START			0xb1
 #define CMD_GET_REVID_VERSION		0xb2
 
+#define CMD_START_FLAGS_CLK_CTL2_POS	4
 #define CMD_START_FLAGS_WIDE_POS	5
 #define CMD_START_FLAGS_CLK_SRC_POS	6
 
+#define CMD_START_FLAGS_CLK_CTL2	(1 << CMD_START_FLAGS_CLK_CTL2)
 #define CMD_START_FLAGS_SAMPLE_8BIT	(0 << CMD_START_FLAGS_WIDE_POS)
 #define CMD_START_FLAGS_SAMPLE_16BIT	(1 << CMD_START_FLAGS_WIDE_POS)