3 files changed, 14 insertions, 5 deletions
diff --git a/Demos/Device/ClassDriver/MassStorage/Descriptors.c b/Demos/Device/ClassDriver/MassStorage/Descriptors.c
index d069bcece..2be052b07 100644
--- a/Demos/Device/ClassDriver/MassStorage/Descriptors.c
+++ b/Demos/Device/ClassDriver/MassStorage/Descriptors.c
@@ -91,7 +91,7 @@ const USB_Descriptor_Configuration_t PROGMEM ConfigurationDescriptor =
 		{
 			.Header                 = {.Size = sizeof(USB_Descriptor_Interface_t), .Type = DTYPE_Interface},
 
-			.InterfaceNumber        = 0,
+			.InterfaceNumber        = INTERFACE_ID_MassStorage,
 			.AlternateSetting       = 0,
 
 			.TotalEndpoints         = 2,
diff --git a/Demos/Device/ClassDriver/MassStorage/Descriptors.h b/Demos/Device/ClassDriver/MassStorage/Descriptors.h
index 3b9a96c8a..674bd2960 100644
--- a/Demos/Device/ClassDriver/MassStorage/Descriptors.h
+++ b/Demos/Device/ClassDriver/MassStorage/Descriptors.h
@@ -68,15 +68,24 @@
 			USB_Descriptor_Endpoint_t             MS_DataOutEndpoint;
 		} USB_Descriptor_Configuration_t;
 
+		/** Enum for the device interface descriptor IDs within the device. Each interface descriptor
+		 *  should have a unique ID index associated with it, which can be used to refer to the
+		 *  interface from other descriptors.
+		 */
+		enum InterfaceDescriptors_t
+		{
+			INTERFACE_ID_MassStorage = 0, /**< Mass storage interface descriptor ID */
+		};
+
 		/** Enum for the device string descriptor IDs within the device. Each string descriptor should
 		 *  have a unique ID index associated with it, which can be used to refer to the string from
 		 *  other descriptors.
 		 */
 		enum StringDescriptors_t
 		{
-		    STRING_ID_Language      = 0, /**< Supported Languages string descriptor ID (must be zero) */
-		    STRING_ID_Manufacturer  = 1, /**< Manufacturer string ID */
-		    STRING_ID_Product       = 2, /**< Product string ID */
+			STRING_ID_Language     = 0, /**< Supported Languages string descriptor ID (must be zero) */
+			STRING_ID_Manufacturer = 1, /**< Manufacturer string ID */
+			STRING_ID_Product      = 2, /**< Product string ID */
 		};
 
 	/* Function Prototypes: */
diff --git a/Demos/Device/ClassDriver/MassStorage/MassStorage.c b/Demos/Device/ClassDriver/MassStorage/MassStorage.c
index 82f02b918..32b4c2634 100644
--- a/Demos/Device/ClassDriver/MassStorage/MassStorage.c
+++ b/Demos/Device/ClassDriver/MassStorage/MassStorage.c
@@ -44,7 +44,7 @@ USB_ClassInfo_MS_Device_t Disk_MS_Interface =
 	{
 		.Config =
 			{
-				.InterfaceNumber           = 0,
+				.InterfaceNumber           = INTERFACE_ID_MassStorage,
 				.DataINEndpoint            =
 					{
 						.Address           = MASS_STORAGE_IN_EPADDR,