diff --git a/README.rst b/README.rst
index d8f0f543..eb86b62d 100644
--- a/README.rst
+++ b/README.rst
@@ -1,7 +1,7 @@
 USB Audio Shared
 ................
 
-:Latest release: 6.3.3alpha5
+:Latest release: 6.4.0beta0
 :Maintainer: xross
 :Description: USB Audio Shared Components. For use in the XMOS USB Audio Refererence Designs.
 
diff --git a/module_usb_audio/devicedefines.h b/module_usb_audio/devicedefines.h
index de3020a6..5de1ee28 100644
--- a/module_usb_audio/devicedefines.h
+++ b/module_usb_audio/devicedefines.h
@@ -274,7 +274,7 @@
 
 /* Device release number in BCD: 0xJJMN */
 #define BCD_DEVICE_J             6
-#define BCD_DEVICE_M             3
+#define BCD_DEVICE_M             4
 #define BCD_DEVICE_N             3
 
 #ifndef BCD_DEVICE
diff --git a/xpd.xml b/xpd.xml
index b69e14b3..82fe6ffb 100644
--- a/xpd.xml
+++ b/xpd.xml
@@ -43,6 +43,7 @@
     <release parenthash = "6dffaa379b87011dd364aaaebbcf58f08e156fe1" version = "6.3.3alpha3" githash = "2b536a00da240d713f77114da393e6baa2857521"></release>
     <release parenthash = "62fc22ffc5ca39a5917277fcb97b8d3b7f05b311" version = "6.3.3alpha4" githash = "4c4cf162049902f3e532eaae88d48eff196981a2"></release>
     <release parenthash = "b2660cf04e4705b99d027061d7576afc03d7124c" version = "6.3.3alpha5" githash = "104c70b4021d9176f8d1ff7b27741efa63f0ca7d"></release>
+    <release parenthash = "e90ed6b9ec4c366520bbc7546f463bd003f30c59" version = "6.4.0beta0"></release>
     <subpartnumber>XM-004720-SM</subpartnumber>
     <vendor>XMOS</vendor>
     <version_defines>