diff --git a/targets/ARCH/ETHERNET/USERSPACE/LIB/if_defs.h b/targets/ARCH/ETHERNET/USERSPACE/LIB/if_defs.h
index c06656f2dc8a712624cfcb4ec256062bd09793e4..af882660a603bf3810f9eabea3c315a00e0cdc21 100644
--- a/targets/ARCH/ETHERNET/USERSPACE/LIB/if_defs.h
+++ b/targets/ARCH/ETHERNET/USERSPACE/LIB/if_defs.h
@@ -60,8 +60,8 @@
 
 // Packet sizes for IF4p5 interface format
 #define DATA_BLOCK_SIZE_BYTES(scaled_nblocks) (sizeof(uint16_t)*scaled_nblocks)
-#define PRACH_HARD_CODED_SIZE (839*2)
-#define PRACH_BLOCK_SIZE_BYTES (sizeof(int16_t)*PRACH_HARD_CODED_SIZE)  // FIX hard coded prach size
+#define PRACH_HARD_CODED_NUM_SAMPLES (839*2)
+#define PRACH_BLOCK_SIZE_BYTES (sizeof(int16_t)*PRACH_HARD_CODED_NUM_SAMPLES)  // FIX hard coded prach size
  
 #define RAW_IF4p5_PDLFFT_SIZE_BYTES(nblocks) (MAC_HEADER_SIZE_BYTES + sizeof_IF4p5_header_t + DATA_BLOCK_SIZE_BYTES(nblocks))  
 #define RAW_IF4p5_PULFFT_SIZE_BYTES(nblocks) (MAC_HEADER_SIZE_BYTES + sizeof_IF4p5_header_t + DATA_BLOCK_SIZE_BYTES(nblocks))