diff --git a/src/host/ehci/ehci.c b/src/host/ehci/ehci.c
index 49f43a9a..387de5e8 100644
--- a/src/host/ehci/ehci.c
+++ b/src/host/ehci/ehci.c
@@ -439,7 +439,6 @@ pipe_handle_t hcd_pipe_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_endpoint
   TU_ASSERT(p_qhd, null_handle);
 
   qhd_init( p_qhd, dev_addr, ep_desc);
-  p_qhd->class_code = class_code;
 
   //------------- Insert to Async List -------------//
   ehci_link_t * list_head;
@@ -649,8 +648,7 @@ static void qhd_xfer_complete_isr(ehci_qhd_t * p_qhd)
 
     if (is_ioc) // end of request
     { // call USBH callback
-      usbh_xfer_isr( qhd_create_pipe_handle(p_qhd, xfer_type),
-                     p_qhd->class_code, XFER_RESULT_SUCCESS,
+      usbh_xfer_isr( qhd_create_pipe_handle(p_qhd, xfer_type), XFER_RESULT_SUCCESS,
                      p_qhd->total_xferred_bytes - (xfer_type == TUSB_XFER_CONTROL ? 8 : 0) ); // subtract setup packet size if control,
       p_qhd->total_xferred_bytes = 0;
     }
@@ -747,9 +745,7 @@ static void qhd_xfer_error_isr(ehci_qhd_t * p_qhd)
     }
 
     // call USBH callback
-    usbh_xfer_isr( qhd_create_pipe_handle(p_qhd, xfer_type),
-                   p_qhd->class_code, error_event,
-                   p_qhd->total_xferred_bytes);
+    usbh_xfer_isr( qhd_create_pipe_handle(p_qhd, xfer_type), error_event, p_qhd->total_xferred_bytes);
 
     p_qhd->total_xferred_bytes = 0;
   }
diff --git a/src/host/ehci/ehci.h b/src/host/ehci/ehci.h
index b06a6f8b..47d00739 100644
--- a/src/host/ehci/ehci.h
+++ b/src/host/ehci/ehci.h
@@ -192,11 +192,11 @@ typedef struct ATTR_ALIGNED(32) {
 	uint8_t used;
 	uint8_t is_removing;
 	uint8_t pid_non_control;
-	uint8_t class_code;
+	uint8_t reserved1;
 
 	uint16_t total_xferred_bytes; // number of bytes xferred until a qtd with ioc bit set
 	uint8_t interval_ms; // polling interval in frames (or milisecond)
-	uint8_t reserved;
+	uint8_t reserved2;
 
 	ehci_qtd_t * volatile p_qtd_list_head;	// head of the scheduled TD list
 	ehci_qtd_t * volatile p_qtd_list_tail;	// tail of the scheduled TD list
diff --git a/src/host/usbh.c b/src/host/usbh.c
index 7be0376c..ff80ee78 100644
--- a/src/host/usbh.c
+++ b/src/host/usbh.c
@@ -256,7 +256,7 @@ static inline tusb_error_t usbh_pipe_control_close(uint8_t dev_addr)
 // USBH-HCD ISR/Callback API
 //--------------------------------------------------------------------+
 // interrupt caused by a TD (with IOC=1) in pipe of class class_code
-void usbh_xfer_isr(pipe_handle_t pipe_hdl, uint8_t class_code, xfer_result_t event, uint32_t xferred_bytes)
+void usbh_xfer_isr(pipe_handle_t pipe_hdl, xfer_result_t event, uint32_t xferred_bytes)
 {
   usbh_device_t* dev = &_usbh_devices[ pipe_hdl.dev_addr ];
 
diff --git a/src/host/usbh_hcd.h b/src/host/usbh_hcd.h
index 8af454b1..ce446923 100644
--- a/src/host/usbh_hcd.h
+++ b/src/host/usbh_hcd.h
@@ -96,7 +96,7 @@ extern usbh_device_t _usbh_devices[CFG_TUSB_HOST_DEVICE_MAX+1]; // including zer
 //--------------------------------------------------------------------+
 // callback from HCD ISR
 //--------------------------------------------------------------------+
-void usbh_xfer_isr(pipe_handle_t pipe_hdl, uint8_t class_code, xfer_result_t event, uint32_t xferred_bytes);
+void usbh_xfer_isr(pipe_handle_t pipe_hdl, xfer_result_t event, uint32_t xferred_bytes);
 
 
 #ifdef __cplusplus