diff --git a/src/portable/nxp/lpc_usbd/dcd_lpc_usbd.c b/src/portable/nxp/lpc_usbd/dcd_lpc_usbd.c
index d4a86c755..223c39c1a 100644
--- a/src/portable/nxp/lpc_usbd/dcd_lpc_usbd.c
+++ b/src/portable/nxp/lpc_usbd/dcd_lpc_usbd.c
@@ -69,7 +69,7 @@
  * - M3/M4 can transfer nbytes = 1023 (maximum)
  */
 enum {
-  #if __ARM_ARCH_6M__  == 1 // Cortex M0/M0+
+  #ifdef __ARM_ARCH_6M__ // Cortex M0/M0+
     DMA_NBYTES_MAX = 64
   #else
     DMA_NBYTES_MAX = 1023