diff --git a/src/portable/st/stm32_fsdev/fsdev_at32.h b/src/portable/st/stm32_fsdev/fsdev_at32.h
index 3a785bbbd..f7ee89995 100644
--- a/src/portable/st/stm32_fsdev/fsdev_at32.h
+++ b/src/portable/st/stm32_fsdev/fsdev_at32.h
@@ -36,9 +36,14 @@
 #endif
 
 #define FSDEV_PMA_SIZE (512u)
+#define FSDEV_USE_SBUF_ISO 0
 #define FSDEV_REG_BASE  (APB1PERIPH_BASE + 0x00005C00UL)
 #define FSDEV_PMA_BASE  (APB1PERIPH_BASE + 0x00006000UL)
 
+#ifndef CFG_TUD_FSDEV_DOUBLE_BUFFERED_ISO_EP
+  #define CFG_TUD_FSDEV_DOUBLE_BUFFERED_ISO_EP 0
+#endif
+
 /****************************  ISTR interrupt events  *************************/
 #define USB_ISTR_CTR                         ((uint16_t)0x8000U)               /*!< Correct TRansfer (clear-only bit) */
 #define USB_ISTR_PMAOVR                      ((uint16_t)0x4000U)               /*!< DMA OVeR/underrun (clear-only bit) */