diff --git a/armsrc/BigBuf.h b/armsrc/BigBuf.h
index ff444f3c8..6bdf4e331 100644
--- a/armsrc/BigBuf.h
+++ b/armsrc/BigBuf.h
@@ -19,7 +19,7 @@
 #define MAX_MIFARE_FRAME_SIZE   18  // biggest Mifare frame is answer to a read (one block = 16 Bytes) + 2 Bytes CRC
 #define MAX_MIFARE_PARITY_SIZE  3   // need 18 parity bits for the 18 Byte above. 3 Bytes are enough to store these
 #define CARD_MEMORY_SIZE        4096
-#define DMA_BUFFER_SIZE         256
+#define DMA_BUFFER_SIZE         512
 
 // 8 data bits and 1 parity bit per payload byte, 1 correction bit, 1 SOC bit, 2 EOC bits
 #define TOSEND_BUFFER_SIZE (9 * MAX_FRAME_SIZE + 1 + 1 + 2)