diff --git a/sound/firewire/bebob/bebob_focusrite.c b/sound/firewire/bebob/bebob_focusrite.c
index 32b864bee25f..06d6a37cd853 100644
--- a/sound/firewire/bebob/bebob_focusrite.c
+++ b/sound/firewire/bebob/bebob_focusrite.c
@@ -27,6 +27,8 @@
 #define SAFFIRE_CLOCK_SOURCE_SPDIF		1
 
 /* clock sources as returned from register of Saffire Pro 10 and 26 */
+#define SAFFIREPRO_CLOCK_SOURCE_SELECT_MASK	0x000000ff
+#define SAFFIREPRO_CLOCK_SOURCE_DETECT_MASK	0x0000ff00
 #define SAFFIREPRO_CLOCK_SOURCE_INTERNAL	0
 #define SAFFIREPRO_CLOCK_SOURCE_SKIP		1 /* never used on hardware */
 #define SAFFIREPRO_CLOCK_SOURCE_SPDIF		2
@@ -189,6 +191,7 @@ saffirepro_both_clk_src_get(struct snd_bebob *bebob, unsigned int *id)
 		map = saffirepro_clk_maps[1];
 
 	/* In a case that this driver cannot handle the value of register. */
+	value &= SAFFIREPRO_CLOCK_SOURCE_SELECT_MASK;
 	if (value >= SAFFIREPRO_CLOCK_SOURCE_COUNT || map[value] < 0) {
 		err = -EIO;
 		goto end;