diff --git a/src/portable/st/stm32_fsdev/dcd_stm32_fsdev.c b/src/portable/st/stm32_fsdev/dcd_stm32_fsdev.c
index 0d566da12..de8802d15 100644
--- a/src/portable/st/stm32_fsdev/dcd_stm32_fsdev.c
+++ b/src/portable/st/stm32_fsdev/dcd_stm32_fsdev.c
@@ -885,11 +885,9 @@ bool dcd_edpt_open (uint8_t rhport, tusb_desc_endpoint_t const * p_endpoint_desc
   case TUSB_XFER_CONTROL:
     wType = USB_EP_CONTROL;
     break;
-#if defined(ISOCHRONOUS_DOUBLEBUFFER)
   case TUSB_XFER_ISOCHRONOUS:
     wType = USB_EP_ISOCHRONOUS;
     break;
-#endif
   case TUSB_XFER_BULK:
     wType = USB_EP_CONTROL;
     break;
@@ -914,20 +912,13 @@ bool dcd_edpt_open (uint8_t rhport, tusb_desc_endpoint_t const * p_endpoint_desc
    * use the same buffer as the double buffer, essentially disabling double buffering */
   pma_addr = dcd_pma_alloc(p_endpoint_desc->bEndpointAddress, buffer_size);
 
-#if defined(ISOCHRONOUS_DOUBLEBUFFER)
   if( (dir == TUSB_DIR_IN) || (wType == USB_EP_ISOCHRONOUS) )
-#else
-  if(dir == TUSB_DIR_IN)
-#endif
   {
     *pcd_ep_tx_address_ptr(USB, epnum) = pma_addr;
     pcd_clear_tx_dtog(USB, epnum);
   }
-#if defined(ISOCHRONOUS_DOUBLEBUFFER)
+
   if( (dir == TUSB_DIR_OUT) || (wType == USB_EP_ISOCHRONOUS) )
-#else
-  else
-#endif
   {
     *pcd_ep_rx_address_ptr(USB, epnum) = pma_addr;
     pcd_set_ep_rx_bufsize(USB, epnum, buffer_size);
@@ -1035,7 +1026,7 @@ bool dcd_edpt_xfer (uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t
   uint8_t const dir   = tu_edpt_dir(ep_addr);
 
   xfer->buffer = buffer;
-  xfer->ff     = NULL; // TODO support dcd_edpt_xfer_fifo API
+  xfer->ff     = NULL;
   xfer->total_len = total_bytes;
   xfer->queued_len = 0;
 
diff --git a/src/portable/st/stm32_fsdev/dcd_stm32_fsdev_pvt_st.h b/src/portable/st/stm32_fsdev/dcd_stm32_fsdev_pvt_st.h
index 40af9b3a5..b64776fc9 100644
--- a/src/portable/st/stm32_fsdev/dcd_stm32_fsdev_pvt_st.h
+++ b/src/portable/st/stm32_fsdev/dcd_stm32_fsdev_pvt_st.h
@@ -66,7 +66,6 @@
       defined(STM32F373xC)
   #include "stm32f3xx.h"
   #define PMA_LENGTH (512u)
-  #define ISOCHRONOUS_DOUBLEBUFFER
   // NO internal Pull-ups
   //         *B, and *C:    1 x 16 bits/word
   // PMA dedicated to USB (no sharing with CAN)
@@ -76,7 +75,6 @@
       defined(STM32F303xD) || defined(STM32F303xE)
   #include "stm32f3xx.h"
   #define PMA_LENGTH (1024u)
-  #define ISOCHRONOUS_DOUBLEBUFFER
   // NO internal Pull-ups
   // *6, *8, *D, and *E:    2 x 16 bits/word     LPM Support
   // When CAN clock is enabled, USB can use first 768 bytes ONLY.