diff --git a/include/asoundef.h b/include/asoundef.h
index 1f5b9748..e780c658 100644
--- a/include/asoundef.h
+++ b/include/asoundef.h
@@ -121,6 +121,14 @@ extern "C" {
 #define IEC958_AES3_CON_CLOCK_1000PPM	(0<<4)	/**< 1000 ppm */
 #define IEC958_AES3_CON_CLOCK_50PPM	(1<<4)	/**< 50 ppm */
 #define IEC958_AES3_CON_CLOCK_VARIABLE	(2<<4)	/**< variable pitch */
+#define IEC958_AES4_CON_MAX_WORDLEN_24	(1<<0)	/**< 0 = 20-bit, 1 = 24-bit */
+#define IEC958_AES4_CON_WORDLEN		(7<<1)	/**< mask - sample word length */
+#define IEC958_AES4_CON_WORDLEN_NOTID	(0<<1)	/**< not indicated */
+#define IEC958_AES4_CON_WORDLEN_20_16	(1<<1)	/**< 20-bit or 16-bit */
+#define IEC958_AES4_CON_WORDLEN_22_18	(2<<1)	/**< 22-bit or 18-bit */
+#define IEC958_AES4_CON_WORDLEN_23_19	(4<<1)	/**< 23-bit or 19-bit */
+#define IEC958_AES4_CON_WORDLEN_24_20	(5<<1)	/**< 24-bit or 20-bit */
+#define IEC958_AES4_CON_WORDLEN_21_17	(6<<1)	/**< 21-bit or 17-bit */
 
 /** \} */