diff --git a/epan/dissectors/Makefile.common b/epan/dissectors/Makefile.common
index 0350058dc9..85f77e9235 100644
--- a/epan/dissectors/Makefile.common
+++ b/epan/dissectors/Makefile.common
@@ -967,6 +967,7 @@ DISSECTOR_INCLUDES =	\
 	packet-umts_rrc.h	\
 	packet-umts_rrc_ies.h	\
 	packet-umts_rrc_pdu_def.h	\
+	packet-usb.h	\
 	packet-vines.h	\
 	packet-vlan.h	\
 	packet-wap.h	\
diff --git a/epan/dissectors/packet-usb.c b/epan/dissectors/packet-usb.c
index 064b7774de..71b5a967cf 100644
--- a/epan/dissectors/packet-usb.c
+++ b/epan/dissectors/packet-usb.c
@@ -39,6 +39,7 @@
 #include <epan/emem.h>
 #include <epan/conversation.h>
 #include <string.h>
+#include "packet-usb.h"
 
 /* protocols and header fields */
 static int proto_usb = -1;
@@ -104,36 +105,7 @@ static gint ett_descriptor_device = -1;
  */
 #define NO_ENDPOINT 0xffff
 
-/* there is one such structure for each device/endpoint conversation */
-typedef struct _usb_conv_info_t {
-    guint16 class;		/* class for this conversation */
-    emem_tree_t *transactions;
-} usb_conv_info_t;
 
-/* there is one such structure for each request/response */
-typedef struct _usb_trans_info_t {
-    guint32 request_in;
-    guint32 response_in;
-    guint8 requesttype;
-    guint8 request;
-    union {
-        struct {
-            guint8 type;
-            guint8 index;
-        } get_descriptor;
-    };
-
-
-    /* used to pass the interface class from the
-     * interface descriptor onto the endpoint
-     * descriptors so that we can create a
-     * conversation with the appropriate class
-     * once we know the endpoint.
-     */
-    usb_conv_info_t *interface_info;
-
-
-} usb_trans_info_t;
 
 typedef enum { 
   URB_CONTROL_INPUT,
@@ -169,8 +141,6 @@ static const value_string usb_langid_vals[] = {
     {0, NULL}
 };
 
-#define IF_CLASS_UNKNOWN		0xffff
-#define IF_CLASS_MASSTORAGE		0x08
 static const value_string usb_interfaceclass_vals[] = {
     {IF_CLASS_MASSTORAGE,	"Mass Storage Class"},
     {0, NULL}
@@ -918,7 +888,7 @@ dissect_usb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent)
         {
         proto_item *item;
 
-        item=proto_tree_add_uint(tree, hf_usb_bInterfaceClass, tvb, offset, 1, usb_conv_info->class);
+        item=proto_tree_add_uint(tree, hf_usb_bInterfaceClass, tvb, offset, 0, usb_conv_info->class);
         PROTO_ITEM_SET_GENERATED(item);
         }
         break;
@@ -926,7 +896,7 @@ dissect_usb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent)
         {
         proto_item *item;
 
-        item=proto_tree_add_uint(tree, hf_usb_bInterfaceClass, tvb, offset, 1, usb_conv_info->class);
+        item=proto_tree_add_uint(tree, hf_usb_bInterfaceClass, tvb, offset, 0, usb_conv_info->class);
         PROTO_ITEM_SET_GENERATED(item);
         }
         break;
diff --git a/epan/dissectors/packet-usb.h b/epan/dissectors/packet-usb.h
new file mode 100644
index 0000000000..c0004df45d
--- /dev/null
+++ b/epan/dissectors/packet-usb.h
@@ -0,0 +1,59 @@
+/* packet-usb.h
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef __PACKET_USB_H__
+#define __PACKET_USB_H__
+
+/* there is one such structure for each device/endpoint conversation */
+typedef struct _usb_conv_info_t {
+    guint16 class;		/* class for this conversation */
+    emem_tree_t *transactions;
+} usb_conv_info_t;
+
+/* there is one such structure for each request/response */
+typedef struct _usb_trans_info_t {
+    guint32 request_in;
+    guint32 response_in;
+    guint8 requesttype;
+    guint8 request;
+    union {
+        struct {
+            guint8 type;
+            guint8 index;
+        } get_descriptor;
+    };
+
+
+    /* used to pass the interface class from the
+     * interface descriptor onto the endpoint
+     * descriptors so that we can create a
+     * conversation with the appropriate class
+     * once we know the endpoint.
+     */
+    usb_conv_info_t *interface_info;
+} usb_trans_info_t;
+
+#define IF_CLASS_UNKNOWN		0xffff
+#define IF_CLASS_MASSTORAGE		0x08
+
+#endif