diff --git a/common.h b/common.h
index dc638fc..3849af2 100644
--- a/common.h
+++ b/common.h
@@ -24,7 +24,7 @@
 #define QFTRANS_COMMON_H
 
 #define RAWPACKET_SIZE 9
-#define DATA_BLOCK_SIZE 256
+#define DATA_BLOCK_SIZE (64*1024)
 #define DESCRIPTOR_STRING "QFTH"
 
 namespace qftrans {